You know, that's an interesting concept. When making such a chimera should you base the proportions on the head vs. body size, or where the feet would actually hit the ground, leaving the height the same?
For example: The dark haired TDI chick is 1-1/2 heads from chin to crotch. The Jane body is 2 heads for that measurement. Using the Jane proportions may make the head look better on that body, but will make her feet go down out of the picture frame. Go the other route and the head looks freakishly large.
Not that I took that much time to measure or thought too much about it. It never occurred to me that someone would look at that abomination of a picture and say "that looks weird because the proportions are off."
So, yeah, you have a point. My uncaring proportions made this look worse that it could have. But I don't think it invalidates my opinion that mixing styles in an edit is a) off-putting and b) not what most requesters would be happy with. But good eye, mate.