Why a senior officer is sent to depot command

Was Crutchley sent to depot command for experience, or because he had been sidelined?

It could serve as useful experience and a temporary holding post. A preferred command may already be occupied by a competent officer.

The answer rejects a simple choice between punishment and advancement. A depot posting could provide useful experience while senior leaders decided what to do next, and it also solved the practical problem of placing an officer when desirable commands were already filled. Giving him another officer's successful command merely to meet career expectations would disrupt a working structure. He later commanded the Australian Squadron for two years and remained in post after the loss of Canberra, evidence against treating the depot appointment as permanent rejection.