High kfenk, are the 4 juvies related to the breeding trio?
Personally I'd leave the trio to work out what they are doing , maybe get a few more clutches of eggs off first.
Also have you thought of doing it the other way around- moving all the L104's in to the 90L and all the B/N into the bigger tank - the L104's stay pretty small and don't require a hell of a lot of room to move( just a thought)
And over all why not leave the 4 juvies in the 220L as your cleaning team.
Only suggestions
J