If you want all enemies at the start, how about Francesco's mod?
http://www.tesnexus.com/downloads/file.php?id=2518
Yeah, I run FCOM, but there are still a lot of leveled lists throughout the game as a whole, and I'd like to take everything to a later point in the game.
If you are using Wrye Bash you can just use Update NPC levels.
Edit.
About just the thread title, I dont know what artificial or not when playing with Oblivion mods, all is codes over codes. Now "natural" should be some thing that balance your gameplay.
Forgot all about the update NPC level thing, haha, but I don't think that would effect loot? Hmm...
And yeah, I realize "Artificial" was an odd term, but I really meant in a cheat-like way; I either get sick of my characters or change builds too often to get to spend enough time in the meta-game, and wind up playing through levels 1-10 over and over and over again