Numberfag time after their debuts:
Clara - 4.45k
Yuu - 3.48k
Memory - 3.36k
Loki - 3.32k
Pico - 3.23k
They're all pretty close but Clara is obviously the breakout talent because of the EN advantage. In terms of future growth, I can definitely see Yuu seeing some growth if she cozies up with the JP FPS streamer scene. The JP scene has also had a renewed interest in LoL, so Clara could see some growth there as well, especially if the rumors about Shibuya Hal making a LoL vtuber tournament are true.