The problem with mixing lions with triggers and puffers is the possibility that the puffer and trigger, may nip at the lions fins.
With that said a porc puffer will ewventually outgrow a 75 gallon tank. It may work for a couple of years if you purchase an extremely small puffer.
At full size the huma may be a problem in a 75 as well. He would last a few years in a 75, but if you wish to keep other fsh with him, I would recommend a bigger tank.