Let use Lovelive as basic for the sake of argument, generation would be Muse, Aqours, etc.
sub unit would be Guilty Kiss (from Aqours), or Bibi (from muse).
if Hololive really goes for subunit production then Yagoo is finally playing idolm@ster or Lovelive right now. If they get super success they will pioneer next Gen of 2D Net idols. Not to mention how promotion collab opportunities from other like the curry promotion with Subaru, Aqua and Pekora (duck, onion and carrot). With China market and entertainment turns shit show (more restriction on gaming and
Anime is being pushed by emperor Xi just now)
This will make more JP companies go back and focus more to internal promotions and other market other than China so it will surely be busy for Vtubers for sure. Ironically this will make next HoloJP and EN generations application extremely competitive so a lot of drama that us degenerate kiwi will love.