Then u have to look for a single or 2 head one lor...My 3 head already open up to more than 5 inches liao...and because my sand bed is filled with my sun, supersun and rhizos, i put it on my rocks high up where they can't sting any other corals...
They can't roam because they are stuck to their skeleton...
Anamones don't roam much actually. if they find a place where they are comfortable, they can be there for months...and they won't roam especially if they have a clownfish hosting in them.