>>869717broski the reason they don't sherpa the sleeves is for comfort and general ease of wear. having puffy clumpy arms on an already puffy jacket sucks. as long as you're wearing normal /winter-out/ layers you'll be fine.
if you don't want to or can't invest in a full-body silver at least get yourself a decent wool or synthetic topsilver (which frankly you should already be wearing anyway) and you'll be fine!
puffy shitty parka arms are for kids man