The late great Isaac Guillory said when he was asked why he used the pinky on his right hand: "Because I've got one"

Classical players often use imimimim for scale runs and pima fro arpeggios. Pinkies are seldom used except in flamenco styles.

Rules are for guidance not obedience: you may be told all sorts of rules - ask the reason, and if the rulegiver hasn't got a reason, ignore the rule.

Stu