/target [target=main, exists, nodead][target=slave1, exists,
nodead][target=slave2, exists, nodead][target=slave3, exists, nodead]
/pr target
This is what I was looking for, I think I'll give it a try and see what I can come up with. By ordering the slaves' ranking in the targeting, I can select who would be promoted based on group priority in target assignment. I would obviously want to assign my healing priest to leader last for instance.