I don't think it's a tradition. There are more and more cases of all male teams, inlcuding for example the fathers of Chouji, Ino and Shikamaru. There are probably many other male teams that were formed AFTER the so-called "tradition" you say was started by Jiraiya, Oro and Tsunade. And we have no way of knowing about the 2nd or 3rd Hokages.