I don't see this as a big problem, becuase when that happens full casters don't have enough turns to use all their slots in combat anyway unless they are low level AND it is a longish battle. There are very few fights that will last long enough. Even a 5th level wizard has 9 slots, so he cares if he has 5 or 9 when the fight is only generally 3 rounds?I think the issue mainly arises from screwing the short/long rest ratio. If there doesn't happen that much stuff in one day and casters get their spells back every day, they will obviously have a huge amount of spells to burn for that one fight that might occur or to trivial problem solving.
Further if you are fighting 1 fight a day with no short rest, 4, 5 or 6 battlemaster maneuvers is still a lot to use in that one fight unless it is unusally long. You can force use them no doubt, where a wizard probably can't actually use all his even if he tries to waste them. But that is not really relevant, because the 7th-level wizard who goes to bed with 5 unused slots left over didn't really do anything more spectacular than the battlemaster who goes to bed with 1 dice.
To be honest I think the 1-encounter a day while traveling dynamic favors the EK and AT more than any other class/subclass. Those classes come to the fight as a full fighter or full Rogue, with all the fighter/Rogue abilities while still having more spells than they are probably going to use anyway. You can add the Paladin and Ranger to that but their spell selection is not as good.