Near as I can tell, off-the-rack men's clothes are pretty much all styled to fit Mister Potatohead: round body, big in the middle, and short toothpick-sized arms and legs. I was just out shopping last night for some more wardrobe options for today (6:00AM call time...whee!). I don't trust wardrobe departments unless we have a lot more prep time, so I usually pick up something myself, in case the wardrobe department has, once again, completely failed to get anything that will actually fit. But it's not at all easy to find anything that fits my sleeve and inseam sizes (both 38"), anything that fits in the shoulders is large enough for me and another two cast members around the waist, as is anything that fits over my thighs. Used to be much worse before "baggy" was in--except, of course, "baggy" is just a code word for "actually does fit over the thighs instead of inside them."
Had my share of problems with tailors, too. I've gone in to have suits taken in around the waist and had them take in the chest to the point where I couldn't put them on. I don't understand this; this is after doing all the measurements and "marking up with chalk" stuff.
But at least clothes shopping must be easy for anyone whose body was designed by Hasbro.