So I kinda hate that CB Shinobi schools suffer just for not being in Court of Stone. So here is my homebrewed solution:
Shinobi from the CB may swap one ninjutsu technique from their school curriculum with any other equal level or lower ninja technique at each school rank.
E.g. a Hiruma Scout that is rank 2 may learn Skulk (a rank 1 ninjutsu) from her curriculum, or may swap Skulk for any other rank 1 ninjutsu, but then may not learn Skulk, or any other ninjutsu technique from her curriculum until she reaches rank 3.
Thoughts?