Deeper gears less effective ?

Less effective at what? What is the goal in what application?
In racing, gears are selected to get the engine into the powerband and at some point, keep it there across the stripe to give the best ET/MPH. The trans type, gearing, and converter has an effect through that process, obviously.
On a street car, it's more about fuel efficiency, efficient torque range, and cruise rpm on the highway.

Cam duration is going to have a big effect on what gear works best for a combination. A 2.94 or 3.23 rear gear isn't going to make an engine happy that has a lot of duration (whatever "a lot" is).

I don't think you can apply simple math to the problem. There are too many variables.