Aside from OL, what position group do the Bengals need most improvement?

[Fan_in_Kettering]

The defensive line, after the offensive line, should be ripe for an upgrade. I looked at film from 2012 to the present and the entire defensive line, especially the right side, is much slower off the snap now than they were back then. Even mediocre offensive lines stand them up in the run game. The Bengals built their defensive line around the north to south bull rush against the pass and forgot the linemen also need effective lateral movement to close gaps against the run. I like what I see in Geno Atkins but even he is getting to the quarterback a bit late hence his sack total is decreasing while his knock down or hurry statistics are increasing. Carlos Dunlap is great at batting down passes but he's no longer a credible sack threat. Michael Johnson is good at taking up two blockers but seeing him drop into coverage makes my stomach queasy. Moving Margus Hunt from end to tackle makes lots of sense and I would like to see him get more snaps and maybe see Domata Peko get less snaps.