I found this in the Chinese translated text of probably the Indian Theravada branch vinaya text (rules of monks/nuns commentary)which has this explanation for the superiority of being a man. For example in the past you might have been a woman but in the perfections one change to male sexe. Because one does good. It changes. So Buddhas are said to work for good in the past as Bodhisattva so the amount time they kept changing back and forth can a lot. But it’s probably how nature works. Because for example being born a man we naturally strong and can withstand certain conditions. So there the perfections is noticeable. It can been seen when we are asked from our wife to certain things that also is sign that mentality also a male just means you trained in past and got born as male. But what if then you do bad, then your chances of being born a female is possible. Woman has to suffer if they get pregnant. Man just gets mental stress waiting 
[edit] I forgot to add this mean that eventually a woman like seen in Jatakas will also become a male Buddha. Arahants are male and females. But Buddhas are highest perfections so it always leads to a male version.
