Yeah, I don't dismantle if I know I could use that higher power on another weapon with the same archetype. In general I know what I need, so when I get duplicates I usually swap with the lower power one I have them shard the old one. Or I just immediately infuse it into something I have equipped. Only time I shard a duplicate immediately is when I end up getting 2 or 3 in a row from engram's and have no use for their power level elsewhere (really annoying when that happens).