yes i know what you mean lol. well as for Zelda/Sheik you can main just one if you want, most people do anyway, but i don't think thats using the character at full. some matchs Zelda is kinda bad at are slightly better as Sheik sometimes. Its just like the PT, transforming mid match isn't always viable unless your opponent is trying to recovery or you just respawned making effective use of both in 1 match kinda limited at times. but research on your own and i'll help along with anything else i can.