Some characters in ars magica seem to create very specialised characters and in turn, very specialised aides and familiars. This can lead to a slew of high stat NPCs in the game and that adds to both good and bad inflation of lab totals.
One way to curb the growth is to rule that the effective Magic Theory (MT) of each assistant is capped at the lab leaders MT score.
As normal the leader needs to have the gift and also needs to follow the guidelines for how many lab aides they can have according to their Leadership score.
This additional cap would discourage familiars being used as MT xp dumps, and force player Magi to raise their MT as a higher priority. That is certainly a double-edged sword in terms of how a saga might play out.