Honestly, I think Ayu just decides to go record somewhere when she feels like going there.
As for Kuu, it will be a success in her own right, but I doubt it will be some big thing, or that it'll top Ayu's sales in any way.
So, tbh it really shouldnt be used as a comparison that way
It's too different and too different a situation.
Personally, I can both see FIVE included and excluded. It's not like it was 8 tracks like Mem. and Ayu's quite unpredictable these days, so banking that it's exactly the same just because they're both mini albums is not really the most fail safe thing. It's kind of a versatile release.
I'd like to see it excluded though, considering....the...nature...of the album...