If you keep them segregated, then they won't be able to overcome some of those limitations (especially that "protectiveness" thing on both sides of the aisle) and won't work as well together.
So the guys won't bond together the same way, and the same for the girls. Is that necessarily a bad thing? Just because it's not the same, doesn't make it bad. It could make for better bonding and better understanding in the long run.
Just my two cents!