Depends, do you just mean physically weaker than what most people think a man should be or do you mean in attitude and behavior?
Discussion
Talking more mental/behavioral than physical. Males lacking masculine traits. Also literal trannies.
I would say if they are behaviorally effeminate they are less useful to society than a physically weak man. If you look back on history most of the great inventors and thinkers weren't physically impressive.
I mean, if you're taking into account transfems here, there are physical differences between a cisgender man and a trans girl biologically...