You could be right. Or not.
I wonder how much the hordes of different Nikon models actually compete with each other. I would be surprised if they don't cannibalise market from each other which would mean fewer models (big decrease in admin, inventory and shipping costs) could be more effective, more profitable and less wasteful of resources.
But Nikon's agenda may be different from this. As a matter of corporate pride they may wish to be represented in every possible market niche even at the risk of duplication.
Lee
Given the expertise and market dominating success Nikon and other Japanese optical firms have shown in the past 60 years I would be surprised to learn that they were not aware of how individual binoculars fit into the corporate wide mix of products.