I think a clear start would be better. Suicide or rejoin would do the trick.
Imagine a ranged duel, both players have 12 shots for example. One guy wins is 7 shots, he's got 5 left. Now he clearly won the round, but he has to start the next one at a disadvantage: He has only 5 shots, while the other one has 12. If he's out of ammo, he lost.
Same thing about shields: if I break my opponent's shield, but he kills me after that, I would have a HUGE advantage in the next round - I have a brand new shield after respawn, and he has nothing.