Fellas:
Having worked with, and been trained by umpires of all shapes & sizes, I don't see size being an issue here.
While I'm at one end of the spectrum (5'07/155), I'm also pushing 40..... Many of you are older, have "wear & tear" issues with your body.
None of that matters. I'll take any partner who knows where & when to be somewhere over one who has a "look," but no clue
AR