Ya. Ill reword saying the same thing :P
Take exhaust out of the equation and you max VE will be your peak torque, therefore matching extractors where ever that may be. So you really setup your base torque/power curves by the intake and exhaust just tweaks it.
So this is how I see it, say your best VE is at 4000rpm but you want torque at 2000rpm, by designing a exhaust to get more at 2000 will start to strangle the torque at 4000. You could say your distributing the power more evenly, Id say its wasting intake tuning.
IMO the best exhaust would be four independent runners. You don't wont to disturb the momentum of each cylinder.