I always didn't liked the idea. Dont get me wrong i can agree to graves but after bodies have been buried.
If the bodies will be server straining you can always add 3 or 4 dead body-like replacers (skeleton etc) not actual player remains with player textures...
Another idea that connects to previous one is to give ability to medic to bury and dissect bodies to lvl up medic skill, and give medic ability to see how player died - like sword to face, arrow to the knee...
AND(some poeple will kill me for this idea) to use human body part in alchemy the same way animal parts are used, as well heads for the players that want to stick it on the gate or show proof that he killed bandit to collect bounty...
Bury mechanic would be would be used to prevent from degrading the soil, that can be later not usable for farming or to prevent plague swallowing area if there are too many bodies...
So would you like to battlefields to like this:
Or like this: