We also need to recall that in Hydaelyn, the male miquo'te is not traditionally the bread winner. 'Tis the women who go out and about, lead the pack, form the family, build the empire (much like the opposite is the case for the Roegadyn). Of course, much of this segregation is broken down in Eorzea, probably due to progression - Merlwyb becoming Admiral may have even had an impact.

But if the cat-boys have been the supporting gender for so long, it would make no sense for them to be more powerfully built than the female, else history would have probably run a different course.

Lithe and slender makes purfect sense for the male Miquo'te.