IMO make a new habitat to put the male into when the females arrive. That way, at least the male won't be defending his well-established territorial prerogatives.

It might work to take him out of his present habitat for a week and completely change the interior decorations so that none of it has his scent on it. Then after a week, re-introduce him to the treated habitat with the females waiting. That has a good chance to stop his territorial aggression.

Roger