Thing is, it's hard to say that Yamato is male since it's not a transgender thing imo, but rather towards a specific character. If Kozuki Oden was born biologically a girl and was Kozuki Sukiyaki's daughter, would Yamato still be calling herself a man and would it still make sense?
In the Wano Arc, i believe the only one who is confirmed to be transgender is Kiku, who is born a male but is a girl at heart and also refers herself and addresses herself as such.
Yamato is acting like a male because that is what Oden would have done, i.e going to the men's bath etc. And Yamato wants to be like Oden.