Not really. Weighted vertices help but in the end accomplish only so much. There's no magic bullet of technology which will correct fundamental structural errors like a malformed shoulder/armpit aream. There's a reason characters are usually modeled in the arms out position.
Frankly the model wouldn't need much tweaking to correct the problem (just pull a few vertices up so that the armpits are higher and the shoulders aren't sloped downward) but it is something to be aware of.
Frankly the model wouldn't need much tweaking to correct the problem (just pull a few vertices up so that the armpits are higher and the shoulders aren't sloped downward) but it is something to be aware of.