Why these skandhas?

(Not sure if i should break this down into two questions. Let me know if that's better.) 1. Is Gautama Buddha the originator of the idea of skandhas? 2. The suttas provides multiple accounts of the skandhas characteristics, and their foundational role in dukkha (For instance SN 22.86 ). But does the suttas provide a rationale for the taxonomy into these five particular skandhas? (To clarify, i'm not asking what the skandhas are, or how they function). In other words: *why* rupa, vedana, sanna, sankharas and vinnana? Are the reasons detailed in any sutta? Or should this question be deemed acinteyya?