Welcome back. In a vacuum, that's the right answer. Up against the cap, without a 1st round pick, and with depth needing to be addressed at other positions, it's not that easy.
The metrics showed that Hobbs played well in the slot. He wasn't good on the outside, but his overall PFF grade ranked 60th out of 114 CBs, so to end up middle of the pack he had to have been good in the slot (other advanced metrics back that up). Problem is they already have Bullard there (overall PFF rank of 49th out of 114). If they didn't have Bullard, there likely isn't any talk of moving on from Hobbs.
If they can draft a guy who can play both guard and center (I'm looking at you, Pat Coogan) with a cheap FA veteran guard, I think Banks is the easiest to move on from. CB isn't very deep in this draft, so I don't know that there are many outside options better than the guys they have (Nixon and Valentine ranked in the upper 40s) and those few FAs are going to be expensive.
The problem is if they move on from both but then get skunked in the draft... then what?