yeah, for the most part you have an ideal setup. Occationally I hear of aggression problems with clowns and puffers, but if it done right, and you don't get a demon possessed clown or humu you should be alright with a puffer. I'd ideally want the clown and the humu to be significantly smaller than the puffer tho. They aren't particularly nimble. And if the triggers deside to go after it, he won't be able to fend off an equally sized fish.