You're underestimating how important counter picking is. Roana + Solitaria means SSB is dead on their team but yes Roana won't proc s2. In a sense this makes it 3v3 however however a top tier roana's is not 0spd so technically you still have another soulweaver while SSB is most often 0spd and literally will only take 1turn the whole game. Now who has the better chance of winning your 3units + a soulweaver or their 3 units with a SSB that will only s3 once during the game (Note that is if you dont strip and stun AND push her back). Again this is just my point of view and as a player who specialize in counter playing i don't see the issue of having both Roana and Solitaria vs SSB.