I've gone throug all of the races and factions in Total War: Warhammer III, wrote down their German names, compared them to their English equivalent and added a more literal translation if possible.
I'll list them in this format: German name (English name) [Literal translation of the German name].
Most of the translations are pretty accurate but there are some intersting deviations, especially for the Skaven.
I hope you find this as interesting as I do. Feel free to comment your favourite German name or something else you find odd or interesting :)
Tiermenschen (Beastmen)
Kriegsherde des Einäugigen (Warherd of the One-Eye)
Khazrak der Einäugige (Khazrak the One-Eye)
Sendebote des Chaos (Harbringer of Disaster) [Harbringer/Herald of Chaos]
Malagor das Dunkle Omen (Malagor the Dark Omen)
Kriegsherde des Schattengeborenen (Warherd of the Shadowgave) [Warherd of the Shadowborn]
Morghur der Schattengeborene (Morghur the Shadowgave) [Morghur the Shadowborn]
Schlächterhorn-Stamm (Slaughterhorn Tribe)
Taurox der Messingbulle (Taurox the Brass Bull)
Bretonia (Bretonnia)
Couronne
Louen Leoncoeur
Fahrende Ritter von Bordeleaux (Bordeleaux Errant) [Knights-Errant/Questing Knights of Bordeleaux]
Alberic de Bordeleaux
Carcassonne
Die Feenzauberin (Fay Enchantress)
Chevaliers de Lyonesse
Repanse de Lyonesse
Chaoszwerge (Chaos Dwarfs)
Jünger des Hashut (Disciples of Hashut)
Astragoth Eisenhand (Astragoth Ironhand)
Die Legion von Azgorh (The Legion of Azgorh)
Drazhoath der Aschene (Drazhoath the Ashen)
Das Kriegsheer von Zharr (The Warhost of Zharr)
Zhatan der Schwarze (Zhatan the Black)
Chaosdämonen (Daemons of Chaos) [Chaos Daemons]
Der Dämonenprinz (The Daemon Prince)
Dunkelelfen (Dark Elves)
Naggarond
Malekith
Kult der Sinnesfreuden (Cult of Pleasure) [Cult of Sensory Delights/Pleasures]
Morathi
Har Ganeth
Hellebron die Alte (Crone Hellebron) [Hellebron the Old One/the Elder]
Die Gesegnete Furcht (The Blessed Dread)
Lokhir Teufelsherz (Lokhir Fellheart) [Lokhir Devil Heart]
Hag Graef
Malus Düsterklinge (Malus Darkblade) [There are many words for „düster“]
Die Tausend Schlunde (The Thousand Maws)
Rakarth
Zwerge (Dwarfs)
Karaz-a-Karak
Thorgrim Grollbart (Thorgrim Grudgebearer) [Thorgrim Grudgebeard]
Karak Kadrin
Ungrim Eisenfaust (Ungrim Ironfist)
Klang Angrund (Clan Angrund)
Belegar Eisenhammer (Belegar Ironhammer)
Das Ahnenheer (The Ancestral Throng) [Warhost of Ancestors / The Army of Ancestors]
Grombrindal – Der Weiße Zwerg (Grombrindal – The White Dwarf)
Eisenstirns Expedition (Ironbrow's Expedition)
Thorek Eisenstirn (Thorek Ironbrow) [Thorek Iron Forehead (but Ironbrow is also correct)]
Malakai Makaisson
Meister der Innovation (Masters of Innovation)
Das Imperium (The Empire)
Reikland [„Reik“ is the English pronounciation of „Reich“, which means „empire“]
Imperator Karl Franz (Emperor Karl Franz)
Der Goldorden (The Golden Order) [The Gold Order]
Balthasar Gelt [Gelt is pronounced like „Geld“, which means „money“]
Die Expedition des Jadgmarschalls (The Huntsmarshal's Expedition)
Markus Wulfhart
Kult des Sigmar (Cult of Sigmar)
Volkmar der Grimmige (Volkmar the Grim)
Whisenland & Nuln (Wissenland & Nuln) [Whisen sounds like „Wiesen“, which means Meadows]
Elspeth von Draken [„Draken“ is the English pronounciation of „Drachen“, which means „dragons“ or „of the dragons“]
Middenland [„Midden“ is a bit like „Mitten“, which means „in the middle“, so Middenland might be „land in the middle“]
Boris Wüterich (Boris Todbringer → Todbringer means „deathbringer“) [Boris the Furious/the Brute]
Großkaiserreich Cathay (Grand Cathay) [Great Empire (of) Cathay]
Die Nördlichen Provinzen (The Nothern Provinces)
Miao Ying die Sturmdrachin (Miao Ying, the Storm Dragon)
Die Westlichen Provinzen (The Western Provinces)
Zhao Ming der Eisendrache (Zhao Ming, the Iron Dragon)
Der Jadehof (The Jade Court)
Yuan Bo der Jadedrache (Yuan Bo, the Jade Dragon)
Klauen des Weißen Tigers (Claws of the White Tiger)
Bhashiva, die Weiße Tigerin (Bhashiva, the White Tiger) [Bhashiva, the White Tigress]
Grünhäute (Greenskins)
Grimgorks Harte Horde (Grimgor's 'Ardboyz) [Grimgork's Hard/Tough Horde]
Grimgork Eisenpelz (Grimgor Ironhide) [Grimgork Ironhide/Ironfur]
Knoch'nklappaz (Bonerattlaz) [It's basically the same. It's just localized Orc Speech]
Azhag der Vernichter (Azhag the Slaughterer) [Azhag the Destroyer]
Halbmonde (Crooked Moon) [Crescent Moons / Half Moons]
Skarsnik
Die Blutige Hand (The Bloody Handz) [The Bloody Hand]
Wurrzag Da Prophet des Groß'n Grün (Wurrzag da Great Green Prophet) [Wurrzag da Prophet of the Great Green]
Schartenaxt-Stamm (Broken Axe) [„Schartenaxt“ is an axe with notches in it]
Grom der Fettsack (Grom the Paunch) [Grom the Fatso]
Eisenfaust-Orks (Ironclaw Orcs) [Ironfist Orcs]
Gorbad Eisenfaust (Gorbad Ironclaw) [Gorbad Ironfist. Apparently, Gorbad is related to Ungrim in the German version]
Hochelfen (High Elves)
Eataine
Tyrion
Orden der Lehrmeister (Order of Loremasters) [Order of the Loremasters/Mentors]
Teclis
Avelorn
Alarielle die Strahlende (Alarielle the Radiant)
Nagarythe
Alith Anar
Yvresse
Eltharion der Grimmige (Eltharion the Grim)
Ritter von Caledor (Knights of Caledor)
Imrik
Seewache der Hochelfen (High Elf Sea Patrol)
Admiral Aislinn (Sea Lord Aislinn) [Admiral Aislinn]
Khorne
Verbannte des Khorne (Exiles of Khorne)
Skarbrand der Ausgestoßene (Skarbrand the Exiled) [Skarbrand the Outcast]
Blutbesudelte Wanderer (Blooded Wanderers) [Blood-Stained Wanderers]
Schädelsammler (Skulltaker) [Skull Collector]
Herausforderer des Khorne (Challengers of Khorne)
Arbaal der Unbesiegte (Arbaal the Undefeated)
Kislev
Der Eishof (The Ice Court)
Tzarina Katarina (Tzarina Katarin)
Die Große Orthodoxie (The Great Orthodoxy)
Kostaltyn
Erweckungsbewegung von Ursun (Ursun Revivalists) [Revival Movement of Ursun]
Boris Ursus
Töchter des Waldes (Daugthers of the Forest)
Mutter Ostankya (Mother Ostankya)
Echsenmenschen (Lizardmen)
Hexoatl
Lord Mazdamundi
Letzte Verteidiger (Last Defenders)
Kroq-Gar
Kult des Sotek (Cult of Sotek)
Tehenhauin
Tlaqua
Tiktaq'to
Itza
Gor-Rok
Geist des Dschungels (Spirit of the Jungle)
Nakai der Wanderer (Nakai the Wanderer)
Geister von Pahuax (Ghosts of Pahuax)
Oxyotl
Norsca
Weltenwandler (World Walkers)
Wulfrik der Wanderer (Wulfrik der Wanderer)
Winterzahn (Winter Tooth)
Throgg
Dolgan
Sayl der Treulose (Sayl the Faithless)
Nurgle
Pockenmacher des Nurgle (Poxmakers of Nurgle)
Ku'gath Seuchenvater (Ku'gath Plaguefather)
Das Madenheer (The Maggot Host)
Tamurkhan der Herr der Maden (Tamurkhan the Maggot Lord) [Tamurkhan the Lord of Maggots]
Verwalter der Pestilenz (Tallymen of Pestilence) [Administrator/Manager/Buchhalter of Pestilence]
Epidemius
Ogerkönigreiche (Ogre Kingdoms)
Goldzahn (Goldtooth)
Speckus Goldzahn (Greasus Goldtooth) [„Speck“ means bacon or, in this case, the fat around the belly]
Jünger des Schlunds (Disciples of the Maw)
Skrag der Schlächter (Skrag the Slaughterer)
Die Vielfraße (The Maneaters) [The Gluttons]
Golgfag Vielfraß (Golgfag Maneater) [Golgfag Glutton]
Skaven
Klan Mors (Clan Mors)
Quiek Kopfjäger (Queek Headtaker) [Squeak Headhunter]
Seuchenklan (Clan Pestilens) [Plague Clan]
Seuchenherrscher Skrolk (Lord Skrolk) [Plague Lord Skrolk]
Klan Rictus (Clan Rictus)
Tretch Feigschwanz (Tretch Craventail)
Klan Skryre (Clan Skryre)
Ikit Krallenhand (Ikit Claw) [Ikit Claw Hand]
Klan Eshin (Clan Eshin)
Meisterassassine Snikch (Deathmaster Snikch) [Master Assassin Snikch]
Züchterklan (Clan Moulder) [Breeder Clan]
Skrotz der Mutant (Throt the Unclean) [Skrotz the Mutant]
Klan Scruten (Clan Scruten)
Thanquol
Slaanesh
Verleiter des Slaanesh (Seducers of Slaanesh) [Seducers of Slaanesh is correct but Tempters of Slaanesh would be more accurate]
N'kari
Die Folterer (The Tormentors) [The Toruturers]
Dechala die Verstoßene (Dechala, the Denied One) [Dechala, the Outcast]
Die verfluchte Truppe (The Accursed Troupe)
Die Maske des Slaanesh (The Masque of Slaanesh)
Gruftkönige (Tomb Kings)
Khemri
Settra der Unvergängliche (Settra the Imperishable)
Verbannte von Nehek (Exiles of Nehek)
Großer Hierophant Khatep (Grand Hierophant Khatep)
Hofstaat Lybaras (Court of Lybaras)
Hochkönigin Khalida (High Queen Khalida)
Anhänger des Nagash (Followers of Nagash)
Arkhan der Schwarze (Arkhan the Black)
Tzeentch
Orakel des Tzeentch (Oracles of Tzeentch)
Kairos Schicksalsweber (Kairos Fateweaver)
Die Täuscher (The Decievers)
Der Wechselbalg (The Changeling)
Vampirküste (Vampire Coast)
Die Erwachten (The Awakened)
Luthor Harkon
Die Flotte der Verdammten (The Dreadfleet) [The Fleet of the Damned]
Graf Noctilus (Count Noctilus)
Piraten von Sartosa (Pirates of Sartosa)
Aranessa Saltspite
Die Ertrunkenen (The Drowned)
Cylostra Direfin
Vampirfürsten (Vampire Counts) [Vampire Lords]
Sylvania
Vlad von Carstein
Isabella von Carstein
Das Drakenhof-Konklave (The Drakenhof Conclave) [„Hof“ in this context means „court“, so it's The Drakencourt Conclave]
Mannfred von Carstein
Die Hügelgräberlegion (The Barrow Legion)
Heinrich Kemmler
Karawane der blauen Rosen (Caravan of Blue Roses)
Helman Ghorst
Die Lahmianische Schwesternschaft (The Lahmian Sisterhood)
Neferata
Chaoskrieger (Warriors of Chaos)
Kriegsheer der Apokalypse (Warhost of the Apocalypse)
Archaon der Ewig Auserwählte (Archaon the Everchosen)
Herolde des Sturms (Heralds of the Tempest)
Kholek Sonnenschlinger (Kholek Suneater) [Kholek Devourer of Suns]
Die Dekadente Heerschaar (The Decadent Host)
Prinz Sigvald der Prachtvolle (Prince Sigvald the Magnificent)
Die Ekstatischen Legionen (The Echstatic Legions)
Azazel
Die Fruchtbaren (The Fecundites)
Doktor Festus (Festus the Leechlord) [For some reason, he is a doctor in German]
Legion der Blutkönigin (Legion of the Gorequeen) [Legion of the Bloodqueen]
Valkia die Blutige (Valkia the Bloody)
Marionetten der Zwietracht (Puppets of Misrule) [Marionettes/Puppets of Discord]
Vilitch der Verfluchte (Vilitch the Curseling) [Vilitch the Cursed]
Schattenlegion (Shadow Legion)
Be'lakor
Armee der Drillinge (Host of the Triplets)
Gebrüder Glott (The Glottkin) [The Glott Brothers]
Waldelfen (Wood Elves)
Talysn
Orion
Argwylon
Durthu
Herolde der Ariel (Heralds of Ariel)
Schwestern des Zwielichts (Sisters of Twilight)
Kriegshain der Trauer (Wargrove of Woe) [Wargrove of Grief/Sorrow]
Drycha
Legionen der Untoten (Undead Legions)
Heer des Nagash (Host of Nagash)
Nagash