Theres 2 primary ways to frag zoanthids/palythoas. 1 is chisel the rock theyre on, breaking the rock apart, yet fragging them into small colonies. The other is to use a fresh razor blade and cut the stalk. Cut as close as you can to the bottom (where the polyp and the rock meet). Zoanthids have a matt, so its possible to frag multiple polyps at once. My palythoas are moreso individuals with little strands connecting each other on the rock (connecting to the mother), so its hard to frag multiple palys at once. I recommend the chisel method with these.
Also palythoas, their guts will come out and theyre shrivel up, but theyll be fine.