Zoas/Palys and Sps

I have gsp, zoas, palys, and shrooms in with a bunch of different kinds of sps and lps. I have pretty much every combination of them all touching, including a sebae anemone touching a trac brain. The only problem I have seen so far is gsp will kill the polyps on monti and then spread onto the skeleton. Don't ever add gsp it's an un-ending plague!

 

I have had this problem with one of my sps, I had water melon zoes that started to invade my galaxy coral the polyps were getting about a inch towards it and I thought I would have to cut back the polyps.
after a while the polyps near the galaxy started getting white spots on them and dying. At first I thought it was a disease or something. Come to find out after watching my tank when the lights where out the galaxy was sending out sweeper tenicals and they where all stuck on the polyps that where near it. Eventually all the polyps receded back.

I think it has to do with the sps ability to defend itself, galaxy's are known for there aggressive towards other corals. Where something like my pink birds nest wouldn't do anything.