JESTER:
Its going to be hard to prevent "nature" from happening. Lions fish eat shrimp, eating shrimp is preprogramed into their being. The only thing you can hope for it that the lion figures out they are cleaners. I have tried to put cleaner shrimp in my w/ lions....Guess what. slurp.
My hope w/ your lions is that they see the cleaners as cleaners from the day they entered the tank, and hopefully (fingers crossed here) they realize it ain't food.
Give the volitan a couple of month or so, when it starts growing(it should be close to a foot long this time next year), we'll see how long the cleaners last.
Please don't add any more inverts to this tank, your only asking for trouble
my opinion
frank