On this level, it is obvious that letting men compete in women’s leagues is a dreadful thing to do. On the other hand, there is absolutely no discrimination towards men on this level so there is no reason to open up women’s leagues to men. The levels on which women are discriminated are the money they receive and the air time they get. Allowing them to migrate from one league to another is by no means an advantage in itself, but rather the means through which they can receive as many benefits as men do. Men already get those advantages so both sexes are treated equally on the point which is the root of discrimination.  There should still be this differentiation, as indeed a competition between men and women can be very biased in a lot of cases, but what is important is to let those women who can face men head-to-head to so.