It's kind of funny that taking one defensive lineman off of the field actually makes the defensive line itself better.
It is weird to think about, but it's not as simple as that. They're in different alignments with different responsibilities. Jordan (for example) is playing on the right end as opposed to the left end spot he played his first two years. Not only that, but he's the only starter that actually saw majority of the snaps last year. There's no Ellis wasting a spot on the field. Bunkley is going to earn his contract, and Hicks won't just do spot duty.
Throw in young players like Walker, Foster and Jenkins, and there is plenty of reason for optimism. These guys will make everyone else's job easier.