Women are slower, so they can't move around and use the footwork that guys do to get inside to the same extent. Just like HWs are too slow to use Cruz footwork until we get a Mike Tyson. Women are weaker, so they can't punish when they do close the distance like men can. Strength is also the advantage that shorter athletes in a weight class have to make up for height. Women don't get that counter-advantage as much. As much as I can see, height is the only physical attribute that carries over directly from men's MMA without being "downgraded". Since height is important in men's MMA and all the other positive physical attributes are massively "downgraded" in female physiology, height has to be much more important in WMMA.