generally, the term of service is pegged to the rank, not the
HEA, although the HEA has a large influence over the highest rank
achieved.
as for why the term of service is pegged to the rank, i haven
thought of a cogent justification. mabbe they follow the paradigm
tt the more capable should do more?
probably also to expose them so as to prepare them for
potential promotions and higher appointments during reservist.