It's been a while, but I believe that is how the fights in the arena are solved? Last I remember, there were a set number of attacks before both sides incurred a penalty towards their hp, armor, defense, attack and damage until someone was victorious.
I believe that's how the fights in pvp/gvg should be. There should never be an unresolved combat
The "fatigue" aspect of PvP would be perfect if it was implemented into GvG hits, I honestly completely forgot about that, so thanks for bringing it up.