>>910489Everything is timezones.
Watame was popular on /hlg/ before ENs debuted because she streams at EN-friendly hours.
Polka is popular among overseas viewers because her erratic sleep schedule has her up and streaming over night JST, and into EN hours
Gura and Ame stream in the same general timezone
Kiara largely streams at a japanese timezone and only rarely streams into EN hours when her superchat readings go long, which affects her growth relative to her genmates.
Mori's growth slowed during her rough period when she only streamed jp hours and picked back up after she started doing more EN primetime streams (morning japanese time) and EN morning streams (late night japanese time) again.
Everything is timezones. Fanbases are active during the timezone that works for their schedule and follow/watch the girls that stream during those times. That's it.