But aren't men's shoes really wide in the heels?

That's what I've found with so-called "unisex" motorcycling boots. There are very few that I can wear. Motorcycling boots don't need to fit very well - just well enough that they don't cause pain or numbness, and won't come off in a crash.

Most of the boots that are long enough for me in the toe and wide enough in the forefoot, are also so wide in the heel and high in the instep that they pull clear off my feet.