I'd actually recommend the ?-3 be done by 2 on top with the one that moves first only to be as strong to take down the first mob. It will then die to the boss and the rest can continue the RNG fest.

?-4 is pretty much pure RNG but i recommend placing your two fastest at top to move around to the second boss. 1 in the bottom and 2 in the middle as well.

So i went ahead and did my obligatory 100 nutaku points roll. The pot became gold! Catgirl for suuuur---- Gerbera... my second of that girl as well...
Decided to do a 50 gem roll and lo and behold i got the catgirl: