I was talking mainly about human weapon designs. All of the human weapons they've made to date adhere to today's military standards, but with some polish and futurizing.
The SMG recoil makes sense in Halo 2. Bungie added in camera-based recoil to weapons, and that high-ROF bullet hose only rode up when you laid on the trigger.
I can slap a laser aiming module onto an HK USP/Colt M4/HK MP5/etc, and they have iron sights. LAMs are for aim assists and for the "cool factor" of being able to shoot from the hip accurately. :P
Look, all I'm saying is that the scope looks absolutely tacky and cumbersome no matter how you look at it. A red dot sight or laser aiming module would make much more sense and look better.