The bolded part of what you typed doesn't make alot of sense and it's contrary to the description from NC that you posted. Clumping and having defined curls is the only way one would know the size of their curls thus what hair type group they belong to. If there is no clumping and no definition that would be 4b. I have not seen any type 3's that didn't have a clearly visible curl pattern. Type 4a tend to know they are 4a due to a clearly visible curl pattern which would mean clumping is involved. Type 4b does not clump and has no clearly visible curl pattern it is a fluffy cloud.
The poster you quoted made some good points and the fact this debate is ongoing is the reason why hair typing should be thrown out the window.