unless you have ample space for raising a large amount male fighters, i find it best not to separate them unless you have to.
i had 4 fry survive to young adult stage and they all turned out to be males. unfortunately i lost one a few weeks ago, but i still need to sell 2 more, as i still have dad in a tank as well.
issue i have at the moment is, of the 2 i have to sell, 1 has a nipped tail and the other is missing a chunk out of his bottom fin. will have to wait till it grows back.