"You were supposed to bring balance to the Force, not leave it in darkness!!!"
Maybe consider adding protection feature to Arena only and returning game play the way it was for the rest of the game. Arena is by definition only 1 round, so you don't need to recharge protection. But GW, Challenges, L&D hard battles either need some way to recharge Protection, or just go back to way it was.
I 100% agree with this. I didn't care about arena since I know I won't have the time to build a team strong enough to get into the top 100, so I focus on building deep teams to win GW and for the eventual Rancor battles that I hope will take your entire squad.