I’m surprised there are still people who haven’t realized the reason for the male/female pairs in Darlifra is because only females can connect (read: activate) the Franxx.

Having two women pilot a Franxx would be wasteful because that’s 1 less Franxx they’d have on the field. And, two males couldn’t get the thing moving at all.

As for why a pair instead of a solo pilot it’s because while they can activate and somewhat move the Franxx (002 is the mostly the exception) it’s too much strain to move them on their own especially during a battle. The guys purpose is to pilot the franxx so the girl’s can focus on connecting with it.