Scrafty is easily walled by mandibuzz w/ brave bird , crobat is still faster after a dragon dance, druddigon can dragon tail, arcanine & staraptor take litte dmg from crunch/dpunch and ko it, and other common walls like gastrodon, bronzong, can weaken scrafty enough to be revenge killed with a priority mov (medicham fake out, mamoswine ice shard, etc). Not to mention its poor speed, pretty much every scarf mon outspeed it at +1. Without rocks in the field and electrode support I dont see scrafty being that good tbh. I just talked about dd set btw, Bulk up is viable but sucks in general if you ask me.
About Rotom, yeah, you're probably right. Its just that it doesn't strike me as a S pokemon(neither does metagross or other uu) Its not really versatile, has a few counters/checks, suffers 4 move slot syndrome, and its weak to rocks.
this is already too long. Anyway, thx for answering