Wtf, how is it easier to design female characters ??? It might be harder actually.
There's a YouTube video on this subject, actually.
In Overwatch's case, the male characters had more variation in their body shapes. When you compare them to the female characters, the girls all use a similar body frame. Even the heavier females like Mei and Zarya were just using a modified version of that frame. Compare that to the men, who can look very different from each other ( et, Roadhog, Reinhardt, McCree, Lucio, Junkrat, & Bjorn).
In terms of SoulCalibur, I noticed that most of the females had a similar height in SCV. If you compare them using the CaS height system (know it's not 100% accurate, but it's a good indicator), Tira, Pyrrha (& Omega), Leixia, Elysium, Hilde were all size 2. The only exceptions were Viola (between 1 and 2) Natsu (3) and Ivy (4). Those three characters were also the only ones of that those heights for females. Ivy was the only height 4 female and unless you made a CaS, there wasn't any height 5 females. The males characters, on the other hand, were WAY more varied. Multiple males were 3, 4, or 5, along with Astaroth exceeding everything. So, it does seem like more effort goes into varying male anatomy than females