I wouldnt worry about them in the star polyps. Leave them there a little longer til your tank mature. Maybe on your 6th month, you can try an anemone if you want. It's too soon right now to add an anemone.
It's actually good that they're hosting in something right now. You rather see it sleep in something at night rather than floating on top of the tank next to the overflow/pump. Again, I wouldn't rush on the anemone.