You raise a good point in favor of Ogletree and other LBs with the skills necessary to be 3-down defenders. I was comparing pass rushers more with run stuffers than true 3-down LBs.
The thing is, there are not many LBs in the NFL that are not considered liabilities in coverage.
Even the great Patrick Willis came under criticism last year for his coverage (which I think is great for a LB). But when it comes to having one linebacker in the game, they go to NaVarro Bowman because he's a superior cover LB.
True 3-down LBs are quite hard to find, thus the move towards hybrid LB/DBs like Bryan Scott.
I like Adrian Wilson in this kind of role.
However Dareus was 319 at the combine.
A lot of people feel he'd be more effective slimming back down to increase his quickness as opposed to bulking up.