I don't agree. I don't have a PFF subscription but didn't they give Odrick a fairly low grade even for his interior pass rush snaps? I seem to remember reading that somewhere. That would certainly match up with what I saw all year, anyway. Odrick often looked totally spent rushing inside, which is understandable given he was playing a position he's not suited for athletically on run downs and trying to make up the difference with pure effort. That takes a toll on even a tremendously fit lineman such as Odrick. The result was we ended up getting like a 75 out of 100 result from a guy who should be giving you like 85 out of a 100.
Starks is stronger, more experienced and a better athlete than Odrick, especially moving laterally (better/more flexible ankles). He also does a much better job getting in lanes and knocking down passes. Odrick is quicker off the snap and more adept and knifing between blocks. He's also got a higher motor. But he flails at times and ends up on the ground more than he should.
I liked Odrick a lot, don't get me wrong. But Starks is the rarer beast. The only downside is that though he's "only" 29 he's been in the league nine years. What's that Indiana Jones quote? It's not the years, honey, it's the mileage? Starks has some serious NFL mileage on him. But... he's also been exceptionally durable for a defensive lineman. In four years here he's only missed one game.
I can't think of a good reason to let him go. Not one. Nor Soliai. You move Odrick inside and you've got one of the most dynamic rotations in the league at one of the most important positions in the game. They need to figure out the LDE and nickel pass rusher position. Maybe the combination of Odrick and Starks being fresher can provide that extra pass rush. I think that's what they were counting on this year but there just wasn't enough of a rotation to keep guys fresh. Odrick in particular seemed to be playing every snap.
