remember when Ronda Rousey was the top of the world, claiming she could beat up Floyd Mayweather and Cain Velasquez?
well, Ronda fights at 135lb. Cain weighs upwards of 240lb ( UFC Heavyweights only have to weigh less than 265lb, so Cain doesn't do any weight cutting ).
this is an example of what happens in a grappling match between two MEN, one of whom weighs ~240 and the other weighing ~145. true, neither of these men has much grappling experience. but that's not the point. the point is to observe that the larger man can do a one arm curl of the smaller man's body weight.
this is the kind of thing that would happen to Ronda were she to attempt to fight Cain with no handicap. yes, Ronda probably walks around closer to 170 so she's probably bigger than Shane ... but men have more upper body strength than women at any given weight so Shane is probably a pretty accurate representation of the kind of performance she would give.
go to 9 min 40 sec to see the grappling.
now, imagine that Cain isn't simply trying to grapple her, he's also going to be punching the shit out of her. and he's bigger than this body builder guy. and Cain knows a little something something about grappling.
if, and this is a big IF, Ronda is ever dumb enough to climb into a cage with a male
Heavyweight THEN she's going to become a greasy red spot on the floor ... provided the Heavyweight actually tries to hurt her. the idea that she's somehow going to armbar a MAN this big is beyond absurd.