Not having caches is also faction flavor. The faction is supposed to represent a battle-hardened German army in a state of low resources. They made it more playable by removing the crippling resource penalties and nerfing some of the large veterancy bonuses, but pretty much all of OKW units still scale better at vet 5 than allied/ostheer units at vet 3. There has to be some resource penalty still in place to compensate, and I think lack of economy boosting caches is a fair trade off.
The "flavor" existed at OKW's launch. Since then, rivers of tears flowed, and OKW looks now pretty much the same as all factions. Scarce resources, cool and powerful units. Much of this flavor was lost, but at the beginning the faction was so original and different from others. And it's not the only faction who suffered such "let's be all the same" changes. People simply did not suffer the idea of confronting more powerfull units (why is your stick bigger than mine, it's not fair...) even if they came from a poor economy and their number was so limited that losing one it usualy ment GG.
Obviously the community wants mirror factions, and COh2 is slowly going there. The brits are still an original design, as OKW was, but I wonder how much will they resist. They suffered some changes already, but the champion of changes is of course OKW. Compared to what it was at the beginning, it's almost unrecognisable.
By this logic, you can give caches, strategic bombers, etc, despite the fact late 44-45 germany had almost no airforce capabilities....