Not sure how Vet-5 has anything to do with economy and caches, that'd be like saying "Caches or Tanks and Call In Arty", makes absolutely no sense.
It implies focusing on unit preservation as opposed to mass production. OKW has FEWER (more expensive and harder to get without caches) but more elite tanks. Thats the idea. No caches and scavenge gives the OKW that late war feel which relic said is intended. Its sort of the grandpa of all factions. The retired veteran Ostheer composed of ostheer veterans (obers) and new recruits (volks) in a desperate attempt to push the enemies back.