for triggers, you can group the less aggressive speicies providing you have a large enough tank with plenty of rock. Some that come to mind are blue jaw, pink tail, durdgeon, sargassam, niger. Due to aggression avoid the queen, and undulate as they are usually required to be kept by themselves as they grow larger.
Lions can definately be mixed, again you will need a large tank with good filtration as they produce a large bioload. I have 2 volitans in my 220. I have also seen pics on another board of a guys who has only lions in his 240, 6 of them I think, cool tank.
Just dont mix the triggers with the lions.