What need is this trying to fulfill? I'm all for house rules, so if you like it, use it. I'm just curious about this choice. Rebel fighters all have hyperdrives, and don't really have a need to be carried into battle. Imperials are going to launch all their fighters before they engage, so again, don't really need this.
But you just ignore that the Rebel Fighter hyperdrives are worse than that of the capitals. So timing is difficult and its nearly impossible to do really long jumps for them. It can also be a benefit to have your pilots fresh and not already spending hours in their fighters before the fight even began.
And why do you assume both forces had the time (and the will) to launch all fighters?
