Yeah everyone collects differently. I count NC sundance as a different pony, but not hong kong vs. China, where as some might, as well as PP vs. NPP, or all of them if they exist! Some people might only collect one cotton candy, but some might collect FF & CF, Some might collect FF, MO, and the CF earth pony release. The same with the Bowties, AJ's, Medleys, etc... long vs. short hair, nirvanas... and the list goes on.
I personally have 400 brushables in my core collection. there are a few doubles that hang around on top of that, childhood ponies and ponies that just appeal to me despite not being upgrades. Plus petites, ponyvilles, blindbags, plush, G3 So Softs and merch figures. Then there's the massive piles of doubles, baits, trade ponies... I probably have close to 800 all in. No wonder my husband gets frustrated, lol...