Leave them as they are for now, let everybody get used to each other.
You may try putting a mare in with the new gelding, kind of like breaking up his harem a bit at a time. A lot depends on the temperament of your first gelding. I have seen some eventually allow the new guy into the pecking order and I have personally had one that was way aggressive when we tried to add a new guy in with his girls. He would pin them in a corner and whip the crap out of them. We sold him to someone who had a very large area to run with a larger herd of horses. That helped immensely.
A woman can NEVER have too many horses.....