What I do is that I house female per pair (sisters) and have the male rotating through the different pairs.

The males rotates through 3 tubs each spending 2 weeks at the time in each tub, by the time they come back to tub 1 the babies are ready to be weaned and the mothers are ready to be bred again.

Females are never seperated they stay together from breeding to nursing.

I never had any issue this way.