Trans women who are on HRT have very different cocks than do trans women who have not had any sort of hormone therapy.
Some men have less testosterone in their bodies in the first place-- and that may show in the appearance and function of their dicks. But it doesn't follow that those guys are trans anything, or even gay instead of straight.
Plenty of crossdressers are plenty full of testosterone. Their actual manliness is never in question. That kind of guy is expressing his choice of preferred clothing and roleplay
One of those, a friend of mine, is a decorated Vietnam vet and a local hero in his neighborhood, one hundred percent heterosexual, and a self-proclaimed tranny.