I didn't suggest that that is the only defense against her moves, but you seem to be saying that no matter what move / hold someone puts on you, you'd be able to get out of it with mere brute force if only you were 50% stronger. Is that really true?
You're also underestimating the strength difference between women and men. Pound for pound, an untrained man will be about 50% stronger than an untrained woman. With both trained, the difference approaches 100%.
http://www.exrx.net/Testing/WeightLifting/StrengthStandards....
Edit: Whenever I hear comments about women beating men in physical sports, I think about the Williams sisters both losing to the 203th ranked male tennis player, who supposedly didn't try very hard, and according to some reports spent the morning before drinking and playing golf, and smoked between sets.
https://en.wikipedia.org/wiki/Battle_of_the_Sexes_(tennis)#1...
http://www.yourememberthat.com/media/15978/Karsten_Braasch_v...
I seriously doubt that the 203rd ranked male had better technical skills than the Williams sisters. Skill only gets you so far, though.
The stronger you are, the more tiny mistakes you can make before you end up in a position where they can't get out.
Perhaps more devastating is that you need less leverage to put them in a compromising position. It can be the difference of grabbing them in a slightly sub-optimal position, then muscling them into the optimal position. where if you were of comparable strength your sub-optimal grab might not be advantageous at all.
In my experience if someone has done a move on you and has it tight then it is very hard to get out of. However, before the hold is tight then muscling out of it is very much a huge concern for a lighter, weaker fighter. A smaller person usually is quicker and more scrappy. Speed is an asset but there is a reason there are weight classes. Larger opponents are much harder to defeat if both people are in equally good shape and have around the same skill set.
Allow me to put this in terms you may better understand. The secret lies in the Y chromosome. This small chromosome contains the instructions for making males. The way the bones and joints are positioned give males equal in weight to a women a distinct strength advantage. Take this into account along with the male hormonal profile which is vastly different.
The most powerful thing is the male hormonal profile. Testosterone allows you to hold more muscle and less fat. It gives men that burst of strength and horizontal punching power that puts them in an entirely different league. I'm sure you are thinking of outliers, but I'm talking about a well developed athletic male, not a couch potato.
Now you see some men that seem more or less masculine and the same goes for women. Rowdy is for sure a more masculine women. I'm sure this is genetic as well as from her training. Her hormonal profile and bone structure is more masculine although in comparison to a male fighter not so much.