OK, (those would be considered LPS not "softies")
When you say your parameters are good, how are you maintaining them, what ranges, and how stable? Those LPS could also be killing each other, all of them are known to be pretty aggressive.
I don't have a lot of LPS experience, but I see no reason to think that any sort of cleaner creature would help with whatever problem you are having. I would look instability in parameters (like correcting levels weekly vs daily dosing), and physical aggression first. (watch at night via flashlight to look for any sweeper tentacles attacking between the LPS corals)