What would Sayla even do in Zeta outside of die like every other woman in that show did? Kamille was a good kid, just got wrapped up in a war he probably wouldn't have been in if he stayed his ass in that karate class.
More so be there for Char and there dynamic, her helping her brother get better which was part of her drive in Gundam and steer him towards a better path.
if nothing else if she couldn't have succeed it would have been top drama/melodrama that Saga of Gundam is filled with.
Kamille would have left at some point just due to how frustrated he was in the situation, I could see him joining the war but never meeting his mentor Char and Emma (who got ti the roughest in terms of death in Zeta)