This. This is a perfect example of why Firefight is rocking now in Halo: Reach. You can tweak everything, from what type of enemies you face to how the physics work in the game. Want to fight nothing but Brute Chieftans with hammers? Well now you can!
One awesome setting is the ability to turn off reloading. Weapons like the Plasma Rifle are RIDICULOUS without the need to recharge. So much fun.
Check out a Gruntpocalypse gametype with stupid physics setting below.