Average man i see (in UK area) has thick arms like this that fill shirts. They might not be the most aesthetic arms or cut arms but they are a decent size and look at least semi-trained.
It's completely common to pass 9 out of 10 men in the street and all of them have some thick arms that fill sleeves. There's literally nothing impressive about having beefy arms now because all men of all races have them except perhaps East Asians. I even see Indian men with sleeve-fillers.