I don't know if there is anything to it, but a lot of the cyclists on the World Tour teams that are sprinters seem to have short legs for their size. Cavendish, Ewing are a few. But perhaps it's just the muscle mass in their thighs that makes for that perception. I certainly haven't measured or compared pictures side by side.

Curious though what feels cramped about the size of your old bike that had you putting a longer stem on it? I think I have somewhat long legs for my size. 34.5" inseam, 71" tall. I got the smaller of the two sizes according to Specialized that they recommended in their sizing charts. And still the distance from my knees to the bars seems like a lot.

And... is your old bike a Specialized Roubaix or a Fuji Roubaix? If a Fuji, that might explain some of the things that are confusing me about what you say you want compared to what a Specialized Roubaix should already be giving you.