The differences between ISKCON and any given other "Indian" group following Bhaktisiddhanta are substantially greater than the differences between the Indian groups. Therefore, a division between the two is befitting.

Why must we find ONE collective term to classify them? Because sometimes we need to collectively refer to them, but separate from ISKCON. I've also read and heard a great number of representatives of these different branches refer to themselves as "Gaudiya Math".

Then, I think this point is just a matter of wrangling, and I am not willing to engage in wrangling, especially not in Kripamoya ad-hoc style.