zoas are usually okay,
but sps can and hopefully will, grow, encrust, and take up that space relatively quickly. Because of that my preference would be to give them a good 2" separation from one another.
But mushrooms will destroy sps corals. and IMO shouldn't be housed in the same tank. I have a couple of mushrooms that don't rapidly spread, that I'm comfortable with for now, but you really can't know if a mushroom is going to be benign in your tank or if it's going to go ballistic!
but....I also have those blue/purple discosoma mushrooms that grow out of control, and those are causing husbandry, and placement problems for me. These mushrooms are like aptasia to me. I cut them away from the areas where sps corals have began to encrust, but sometimes it's just not possible to get a clean cut, so I often obliterate some of them.
Eventually they will all have to be removed, and I get more aggressive I cut their colony back, but they keep coming faster. From 3 little frags I started last June I've counted approximately 280 known clones that I have now or have distributed! That's probably not even impressive to some coral farmers!
Yeah I feel ya I really like both but if you want to save yourself some trouble separate them now or but ready, willing, and aware of what tasks await you.
cheers,
andy