Oblivion has an army from "hell" that simply wants to destroy for the sake of destruction, you have the ultimately "good" side and the ultimately "evil" side, necromancers are all bad, magic is even more just a tool (that somehow still doesn't flow into how the world is build up), you have ancient elven ruins made of pure white stone, it was FAR more on the idealistic side and you had an ultimate resolution of the story by divine intervention (sending the avatar of akatosh to save the day)... so no, they're NOT on the same level.
Wow. I can tell you're really not an Oblivion fan, because that's gotta be the most simplified version of the game I've ever seen.
1. Oblivion
isn't hell, and the Dremora aren't demons. Sure, Dagon wants to destroy the Empire, but if Mankar Camoran's rantings are anything to go by, it's because he wants to reclaim Tamriel for the "Daedric Prince" Lorkhan, whom I
suspect may or may not be Dagon (and Akatosh!) himself. I get a very Shiva/Vishnu/Brahma feeling off those guys.
2. Necromancers aren't all evil. They don't like you, because hey, you're in the Mages Guild, who're a bunch of stuffy old bigots. Some way to explore the other side of the story would've been nice, but what can you do? Must have something to do with them all being driven underground. Luckily, we can read http://www.imperial-library.info/mwbooks/corpse_preparation.shtmland see that everything's not black and white.
And hey, need I bring up the Dark Lord Dagoth Ur who sits in his Dark Castle, also called Dagoth Ur, sending out his Dark Army to kill the plucky farm boy (check out those vampire dreams) who happens to be nudged onto his path by the wise old wizards (Azura and Vivec) in order to save the Empire? Oh, wait. I already said all that.
Both games are pretty obviously high fantasy (which you proved yourself when you offered up those TVTropes links), but I can see this is going nowhere and is going seriously off-topic, so how about if we just agree to disagree?