if you also have a thing where both of them ladies, then that’s an additional thing and it muddies up the joke. The audience will think, “Why are those characters female? Is that part of the joke?” The underlying assumption there is that the default mode for any character is male, so to make the characters female is an additional detail on top of that. In case I’m not being a hundred percent clear, this thinking is stupid and wrong and self-perpetuating unless you actively work against it, and I’m proud to say I mostly don’t think this way anymore.
This is precisely why diversity is important: if you leave out some types of people, they become typecast as the exotic “other” and it’s difficult to portray them any other way.