(((interference)))
Veteran
If you're talking dead ones, sure. But that's hardly any effort to render. If they're behind walls or off screen, it doesn't count because they're not being rendered.
I mean in the playspace, ie. if you detach the camera and fly to the top of the map you should be able to see that many, barring the few that are in nooks and crannies (ie. no map is completely open)
Are they talking about 40 NPCs on screen in Reach? or just in the general combat environment like a Firefight map.