I agree that those are palys not zoas. The long, thin tentacles are a giveaway. In my experience, palys kill mushrooms every time. I had a rock full of mushies similar to those that was a little too close to some green palys and the whole rockful melted away in a few days.
I don't think the Kenya tree should bother palys or zoas, either. I have KT all over my tank and, in fact, I'm looking at a stalk right now thats lightly brushing up against a colony of delicate zoas without bothering them.
The point is, palys are really toxic and usually win most matchups against other soft coral intruders. After looking at your pic again, I really don't think those are necessarily burned. I have a huge colony of some just like that and they have always kind of been folded and fringed a little on the borders rather than perfectly round. I've always liked that about them and the way they line up to form a big colony.
But by the looks of it, that mushroom is going to lose that battle.