They aren't natural hosting anemones. So 3 things could happen, the clown will ignore it, the clown will be hosted by it, or the clown will be eaten by it.
I personally haven't had issues with any anemone moving around a lot (( excluding new clones )), so if you provided the conditions the anemone requires it shouldn't move. Those anemones can get fairly large. As for your lights, what size tank, and are they daylight bulbs, actinic, 50/50....