>> ...all subsequent knowledge expressed by B may be ignored.
Given that we're human with a finite amount of time and attention at our disposal, it strikes me as intuitively sensible that we tend towards (but never firmly settling on) this outcome, especially where instances of N >> K...a sort of "survival of the fittest" feedback loop, if you will. I think Johnny Lee's analogy framed in the context of the user experience[1] is applicable here.
>> ...it effectively assumes that A's knowledge is a superset of B, and that A's rate of knowledge aquisition is greater than that of B for all T.
Sounds like narcissism. Surely we can have our pragmatic feedback loop without deteriorating into such a state.