It's all personal taste I can't stand gale because he commits far worse crimes and his ending is a professor in the school of magic. He got a really happy ending by comparison and that doesn't sit well with me.
You can always make him sacrifice himself, if you find that more just. Though I don't know what crimes he is supposed to have committed unless you make him commit them.
gale had so much ambition that even being close/ in love/ the muse of mystra wasnt enough and he tried to get more and more and more magic power. When he asked mystra to show him more of the weave and she said no be content and in response he tried chasing down ancient magic with near 0 understanding of it. His crime was unbridled ambition in the face of a life anyone else in his circumstances wouldve been more than happy. Gale went against the goddess of the weave and his punishment is..... a teaching job..... just my 2 cents i know its not everyones opinion or even a popular one but between that and the way he talks he just gets on my nerves.