The size of the pelvic outlet (essentially your sitbone span) has almost nothing to do with bone structure or height or weight.

I've seen tiny women with ginormous pelvic outlets like mine, and I've seen big women like me with itty-bitty ones.

As far as the styles of Terry saddles, I know there are a few folks on here who really know them well. If you have a question about a particular saddle you can start a thread about it, and plenty of knowledgable people will chime in!