Right off the bat, Yeonwoo-ya and Nancy. Their visuals would have been easily hyped to the high heavens by big company stans. I know most just remember them for their short shorts and A.R.M.Ys giving them massive hate for looking at BTS, but obviously a bigger company would be better at managing their style and image.
IDLE Soyeon, Yuqi, Miyeon: They have so much potential as talent + stan attractor + visual combo. They managed to do well under Cube, which says a lot, but in the end mismanagement dealt a huge blow. They can still come back and do well, but if they were Big 3 they'd be 50x popular than they are now.
LOONA Heejin: She has ace potential + visual with Han Sohee vibe.
STAYC Yoon: HUGE it-girl potential. Out of the current tall 4th gen visuals she's would have easily been #1 if she was Big 3
