I agree with most of that. It seems reasonable and fair.
Only problem I have is with what you would say counts as 2 and other count as 1, but everyone will have some gripe here or there
Mine is about the mini-con partners.
I think they should count separately because both figures can still function without the other, it may be reduced, but it still works.
Hasbro/Takara could still market either individually and they could still work, which they have done, they did it with Deluxe Armada Prime and a lot of the partner mini-cons
The mini-con is also interchangeable. In most cases, it doesn't really matter which mini-con you use with the bigger one, you can still get most of the gimmicks working with any mini-con

So for me, any figure that doesn't need the mini-con would count separately.
Figures like Overload with Rollout would count as 1 because Overload can't get to robot mode without Rollout, nor can he get to his shoulder cannon mode without Optimus. He would be stuck in Vehicle mode, which really needs something to drag it around (ie Prime or Rollout)
But Optimus Prime and Sparkplug would count as 2 because Prime could be sold without Sparkplug, or with any other mini-con and still be fine. Same can be said for Sparkplug, which has happened