When I assign a fleet to a hotkey (i.e ctrl 1), and then later I will combine them with another fleet assign the fleet to a new hotkey lets say 2. At this time I now have a fleet which will answer in whole to 2 or just partially to 1. I think that anytime you assign a hotkey to the fleet it should remove the previous hotkey. The only way I have been able to do this is by immediately selecting something else and assign it to hotkey 1, which is a pain. Otherwise am loving the game.