Rancor is all about TM removal. if the rancor doesn't get a turn then he can't hit you. his 55% base to stealth at the start of his turns is good. then he can stealth himself every so often is his lead hasn't already given himself it. the result? he gets stealth the majority of the time. simply put him with either other TM removers or toons that call assists. there's lots of ways to do it.
he's great for both pigs and rancor. with pigs you need a team that can take out the guards and then it's the same as fighting the rancor (although pigs base speed is slightly higher than rancor, they obviously don't devour).