^^^^Greg really says it all. But that doesn't mean I can stay quiet.^^^^^^^^
It sure was a good idea to research the lion before buying one. I may be one of the owners of one of the 6+'' maroon clown dinners namxas refers to. IMO, none of your fish are good tankmates. The lion will certainly eat the clowns and wrasse and the triggers and puffer will constantly harass it. As to size, there just isn't room for much argument on their growth. They can easily reach a foot within a year or so. This is very common. I've raised several babies from a couple of inched to 12"+. I don't know of any commonly kept fish that grows faster. I don't know what a brown trigger is, but lions will eat small triggers, in spite of the little "trigger" fin. Your wrasse, I assume its a lunare, is not a fast grower and is a thin fish. If he isn't small enough to be eaten yet, he soon will be. The clowns being eaten is a sure thing.
I see no option but to return the lion or trade all of your other fish if you decide to get one. Lionfish tanks need to be centered around the lion. They're easy to keep, but can't live with many/most fish. There are plenty of fish that do fine with Volitans, though. Most tangs, large wrasse, many butterfly fish, etc.