I am just now on my first litter, but I have a couple things that might help.

1. I believe hairless females can have issues producing enough milk (someone correct me if it's just the double rexes). So usually they are kept with a regular female just in case, or have a regular female that will deliver at the same time so that you can give some of the pups to her if needed.

2. Some females will fight over litters if kept together when they have babies. If this keeps happening with yours, you may want to split them up.

3. Get rid of the aggressive male that fights the other one. Aggression is genetic and learned and you don't want to breed aggressive animals. If you want males that will live together, get rid of him and only breed calm males that get along. Keep a nice male baby from one of these litters to raise up and if he is calm as an adult, even after breeding, keep him as a breeder.

Good luck!