I would like to suggest keeping them seperate and this is my reason.
I had two clutch mates given to me. One was very healthy the other was okay but needed to be fed more. Because of space I had to house them together for about two months. I watched them eat every day and the very healthy one always ate more, but never bugged the other too badly. They do tend to go for the same crix often, so it's not really aggression, just pigginess! LOL Once I had the chance to seperate them I noticed that the lesser of the two began to grow. Fast! Now he is far bigger that his brother. To get ot the point: it is best ot keep them seperate because in the long run it is bette for them both
It doesn't take much to give them both a 10 gallon or a bigger critter keeper until they are for sure male & female.
Julie