At the end of the day, it really should all go back to what the hardware maker says. Nintendo, Sony and Microsoft all tell us what they consider each "platform" and what hardware exactly falls under each, that dictates what they do with these platforms and really should itself be good enough.
iQue has nearly identical hardware to N64 and runs the same (adapted) games... should we consider it an N64? The Super Game Boy and Game Boy Player actually each housed GB/C hardware inside and literally played GB/C games, should they add to the GB total? Are SMS and Game Gear the same platform, you can play each's games on either with the proper adapters? There are tons of issues that come up when you start defining a "platform" by it's chips alone, there's really more that goes into it than just that.
