you are greatly oversimplifying the issue though. at a given constant rpm at any partial throttle level, there is no difference between a small and large tb. the engine is seeing the same air flow. in terms of WOT, it does not make sense to view the larger diameter tb and the resulting slower flow (just through the length of the tb, mind you) as affecting hp/torque. what matters is the air flow throught the entire system, most importantly at the intake runners going directly into the cylinders. the 3 or so inches which air goes through the tb will not affect the entire systems air flow to the point of a loss of low end torque. however the larger diameter tb combined with a matched intake manifold will allow for significantly increased flow at the top end. there are some good articles out there on this - lemme see if I can find one.

my 2 cents homie