I still don't see the difference between that and men fighting opponents who cut a huge amount of weight? That's not completely commonplace granted, but it its still fairly common to fight someone who is a weight class above you come fight night. Bisping, Sonnen, Rumble and Linekar come to mind. I'm open to the idea you mentioned of having the women with a higher weigh in limit to even it out but I'm still not entirely convinced its necessary and would damage the credibility of any woman who won the fight. People miss weight by a pound now and its blamed if they happen to win after. Letting women weigh in heavier will destroy it. I'm much more in favour of doing it with normal weight classes first and going from there. If it does turn out that in practice the women are clearly losing because they're getting outmuscled (which is a seperate issue in itself since I would expect women to lose more often based purely off women's mma being at a lower level then men atm and then you have to work out whether its askill or power discrepancy that made them lose) then you have a better reason to start messing with alternative limits but doing it from the start sounds like another way to cause opposition to it to me.