It doesn't even work like that in biology al the time. Some small women can take (Warning: Graphic!) 9 plus inches with out as much as a flinch and some large women can barely take 5 inches. Some small men are (no homo) are gifted like a horse and some large men remain toddler status (2-3 inches) their entire lives. It's actually more common, for humans in general to have parity in size throughout an individual's body (unless they are 100% symmetrical.... which is no one on earth.)
Secondly, women control sex. It doesn't matter what men want(unless women are willing). They will hold out if they don't or cannot attract men that they deem desirable. They'll put out if they can. It's really that simple.
I don't claim to have the exact numbers, but, in regards to the premise of your thread, the average woman desires a man with an average size apendage or better. It's less common that a woman is built in such a manner to which she cannot accomodate a male that is average or less (but not impossible).
Lastly, women have science on their side. Whatever they lack, they can buy, and do so. No matter what people or advertisements tell you, it's unsafe to alter your apendage. The risk of losing the ability to use it is greater than any gain that you may receive from surgery or pills. It's not worth it.
Sorry I kinda ranted.... bottom line...
Women control sex.