You are all essentially making the same argument here: SE was, for whatever reason you might choose, forced to release a KH game on handhelds instead of consoles. Because they were on handhelds, they should not have a mainline title. But I don't think any of this disproves that they made a mess by doing this. And despite any financial or logistical reasons, this is all still on Square Enix. That the games with the most important story bits were released as handheld titles with what appears to be spin-off names. This is their mistake, and I don't think it's fair to expect the audience to make up for it. They could have either titled the games in a way that would communicate what they were canonically to the fans better, or they could have held off until they could develop fully fledged KH titles. In any case, this is ultimately not a problem made by the consumers, and expecting them to catch up on this logistical mess is unrealistic.