can you frag blasto's?

A clean cut through a blasto head will enable it to recover and quickly regenerate.
not quite can I tell the difference? it has purple outsides with bright green centers.
the merlettiis have an extended skeletal base the wellsiis have a flat skeletal base
Well with Merlettiis, you can just break off one or more of the skeletal extentions at the base and then mount it on the rockwork with epoxy.
No, they won't grow as fast as that and they're entirely different in form than zoanthids. They need a good level of calcium so that their skeletons can grow unabated, and they'll spread though. They are nice, though the colors the Wellsis come in are more varied. I have five of those in my reef and they spread nicely.