Why don’t we use AS2 and AS1 ranks in RAFAC?

Is there a reason why RAFAC hasn’t bothered to use AS1 (Not including AS1T) and AS2 for more beginner ranks instead of ignoring them and skipping straight to CPL? Like you’d think it makes sense to have them adapted in a way. Like I understand why AS1T and chief tech,LCPL,FSAcr,MAcr,SAcr since they don’t have a place in RAFAC. Or would it be more confusing to have 7 ranks (Cadet included) then just the basic 5 we have at the moment