TES is a shittier Forgotten Realms at this point.
I've never played
TES Online and haven't looked into its lore, but
Lawrence Schick, the dungeon master whose personal campaign setting was the origin of D&D's Known World / Mystara setting, served as the game's lead content designer / writer / loremaster for a decade, so it might well have further inspiration that separates it from the dullness of
TES III: Oblivion.
Although I doubt the original designers of The Elder Scrolls setting, as presented in Arena and Daggerfall, were influenced by the Known World / Mystara, they did take a similar pulp fantasy approach for the human realms. Just as the Known World contains the Northern Reaches (Vikings), the Emirates of Ylaruam (Middle East), the Empire of Thyatis (Roman/Byzantine Empire), and the Grand Duchy of Karameikos (originally conceived as a relatively conventional and generic pseudo-medieval feudal realm), so too does Tamriel contain High Rock (relatively conventional British/French feudalism), Hammerfell (the Middle East), Skyrim (Vikings), and the Imperial Province (Roman/Byzantine Empire).