Since there have been multiple discussions about this in other threads I remember this issue being brought up quite often and I remember one guy had a link to where it said some of the features of Oblivion and one of those features were 5- 8 dungeons designers. Sorry I cannot produce a link or anything but if you seach the forums good enough you will be able to find it.
Do you have a link for when Todd said there was only 1 level designer in Oblivion?
EDIT: Just Googleing I found this https://www.neoseeker.com/forums/22202/t585315-dungeon-info/
"When I joined Bethesda I became the sixth member of a growing dungeon team - the portion of the Oblivion dev team that basically does nothing but design, build, test, and tweak dungeons. We've since added two more dungeoneers to our ranks and as a group, we have now hand-crafted more than 200 subterranean locales to explore and pillage while playing Oblivion."
Wow I read that article and either they are lying through their teeth or they are discussing features that alas didnt make it in the game.
Here's some snippets I found amusing:
"At the same time, we wanted to make sure that the dungeons were unique and memorable - not just a series of cookie-cutter holes in the ground with some loot and a few skeletons" <- hah!
"Throughout the process, the dungeon type (marauder fortress, goblin cave, vampire lair, etc.) determines the architecture we use and the types of spaces the layout can and should use." <- also did not make it into the game. there were forts, caves, ayleid ruins and mines.
"Almost all of the dungeon encounters in Oblivion are leveled to the player, which means that as you progress through the game you will encounter tougher and more varied enemies. Note that this doesn't mean that all encounters are your level - not by a long shot. It just means that your level determines what types of creatures and NPCs you're likely to meet in the deepest, darkest places of Cyrodiil. Sometimes you'll run into low-level critters that you can dispatch with a single fireball; other times you won't be so lucky." <- I dont know wether to laugh or cry at that one.
"You'll also encounter a variety of traps and other obstacles that - like everything else - are tied to the theme of the dungeon. So while bandits will protect their hideouts with hastily assembled log traps and trip wires, the undead lurking in an ancient tomb might have more magical - but equally as deadly - defenses in place." <- lies
"but we've also added a little extra to individual dungeons wherever possible, to further differentiate them from each other."
<- way too little, always seems like an afterthought.
I do hope that this same kind of hype we are now having over Skyrim, some of the statements seem awfully familiar, doesnt turn out to be a load of hot air again.