Why does the $$RFM$$ rubric present the three key measures $($recency$,$ frequency, and monetary value$)$ in that order?

$($: $1)$

This is the order in which they were discovered$/$identified as being highly predictive of future behavior

Recency is the easiest of the three to observe$/$measure

Recency is the most predictive of the three

Recency and frequency are equally important, and monetary value is far less important than both of them