MS has learned from Apple how to make money: make it slim, make it white, make it EXPENSIVE.
The third component is most important in this game. Good for both companies - they can use the
same hardware, no need to introduce concurrence (price drop == less money).
One not touch sensitive clickable encoder (in fact what you already use every day in any mouse for $1), with "click" schema (used in some Logitech devices, I must admit I like it) and some LEDs, in "designer" outfit, WHITE, can be presented as a "all rounder control", and so sold for $100.
Sure, that is better idea (from revenue perspective) then support 2 independent mouse devices ( I am almost sure you will be unable to use second mouse wheel insteed of this "control wheel", while technically they are identical).