I don't understand the reference to desk job and what it would have to with ranks and decorations. While 'an army marches on its stomach' all sorts of experienced people in civilian life were required to order and obtain the food, petrol, ammo needed for the military
Many armies have a group called the ASC and much of the work, in the early stages would have been done by men experienced in desk jobs in civvy street.
'The Army Service Corps (ASC), in the context of the New Zealand army, was the supply and transport branch, providing essential services like food, equipment, and ammunition to the troops, and also assisting in evacuating the wounded'.
(wiki)
It would not have been at all unusual for a colonial civil servant to have been commissioned during the war, but then perhaps because of his skill-set, be assigned desk job
I was discussing this with a senior military person I worked with and he said most military would have frowned on 'conscripting bright young people' especially in the early stages when there was a need for ASC duties and Intel. Later these would have been backed up by women.
Some ranks were entitled to retain their rank after hostilities cease. None of my uncles did.
Also in some areas there was an active undercurrent against men who were perceived, mostly incorrectly, of 'not fighting' during and after the war/s.