Women can definitely accommodate any thickness of cock - there are no 2 cocks together that are thick enough my wife wouldn't be able to handle them and enjoy it. Length though is an issue for many women. If you watch porn with women taking huge dildos, I've seen 12"+ going up the butt but you rarely see a woman get more than 8" or so inside her pussy. So yeah, like cocks, pussies seem to come in different depths... but yeah, if they can get a baby out, cock thickness is not really a problem.
A couple girls I occasionally get with have said they stopped seeing guys because their cocks were too long and they dreaded sex. On one hand, I'm sure it could have been great if the guy showed more restraint / maybe more foreplay. On the other hand, it kind of sucks as a man having to worry about that during sex, so I'm sort of glad my cock isn't much longer.
I'm only like 8" but occasionally if I thrust too hard at the wrong angle, I've gotten a yelp from certain ladies. My ex-girlfriend of many years was rather shallow and I had to be careful. I enjoy my wife's pussy a lot more because I don't have to hold back except in like missionary when her legs are back and I can hit really deep. In recent years she has actually complained my "dick is too big" (which I certainly don't think is the case) and she gets sore but I think it is because she is often tired and a women's vagina elongates when they were turned on. So when she comes home ...... and horny, she wants to get pounded and its no problem but when tired and not as into it, she gets sore and complains.
I'm sure she'd be happy though if it were an inch shorter but twice as thick. I just have to keep working at getting her some DP... She loves the idea but hasn't happened yet.