1. Start Combat Ops scenario.
2. Go to Morton and try to clear it (don't feel bad if you can't do it without dying once or twice - nobody was born a Rambo, except for John Rambo).
3. Notice how the dead bodies start disappearing, before you get from one end of the town to the other.
4. Ponder how immersion breaking it is.
5. Realize that this could be configurable, allowing many people/servers with a decent HW to run a smooth game even with a few dozen bodies still lying around.

My suggestion is to change the body removal system, adding two parameters that can be configured when starting the scenario and/or via settings exposed somewhere in Game Master (allowing the parameters to be adjusted even while the scenario is already running):

1. Maximum allowed number of dead bodies existing in the world at any given time.
2. Minimum delay before any body can be removed.

If parameter #1 is set, and the number of dead bodies reaches the limit, remove the oldest existing corpse (repeat until the number of dead bodies returns below the limit).
If parameter #2 is set, simply keep removing any dead bodies that are older than the desired minimum delay.
If both parameters are set, combine the two methods (optionally prioritizing one over the other depending on the settings, some other choice, or situation).

I can imagine several implementations with various degrees of efficiency and simplicity, so i am sure you can too.
I strongly believe that something like this should be a standard, available in generally every scenario, not just Combat Ops.