You could always try to drag/carry them to a 'dumping' ground that would be a site to see. Gives it that realistic feel I guess as it takes some time for decomposition lol. If not they're there for the rest of the game. Not sure about the PC but on the 360 if there's respawn points they'll respawn.
How do I delete dead bodies from the game (including ash/goo piles) that I kiled months ago? Thanks, because the lack of rigor mortis with these piles of Catpaw Company Mercenaries is getting rediculous.