I don't have twins but I think I'd be inclined to just pool the clothes when they're little. And me being me... the clothes would spend most of their time in a washing pile, so would hardly ever be put away to worry about what goes where

And just as a side point.. those iron on labels do NOT come off LOL. Which is a pain for selling/hand-me-downs. We received hand-me-downs with those labels, and needless to say, if we lose those clothes (school clothes) the original owner will get the phonecall! Unless someone knows a knack for peeling them off?