I think of chompers as rogues the problem is after the kill they just sit around like a stuffed anaconda. They should be able to get in fast , get a kill , and get out.
What I think would work best is after they use swallow they could use burrow again to escape but couldn't swallow another zombie till after the digestion cool down was reached to prevent abuse of the ability. Hp may need to be adjusting to compensate for the new survivability possibly.
In the description chompers are described as hit and run characters but as it stands now they can only hit they can't run. This leaving them nothing to do but go on suicide runs when large groups are present , which in a multiplayer game is all the time.