I'm curious, why in your mind is that a petty thing to mandate? The issue is OKW doesnt have caches right? But they do have another resource income ability that is a bit micro intensive but pretty useful, especially team games. Why should OKW be redesigned to have no resource penalties, given caches that breaks your favored asymmetric balance paradigm, while also keeping salvage? Just because you want it?
What I'm getting at is this game fosters these unproductive arguments around balance because the WFA were so poorly designed from the jump and because of this, you feel the need to protect your favorite mechanics or unique items instead of just saying "you know what we should all have caches because its a basic mechanic at the core of the game and that would also mean we shouldnt additional resource bonuses other factions do becuase its a basic mechanic at the core of the game."
You seem to understand the first part well, "we need this because its core game mechanic" but you're not understanding the second part so well, especially considering balance is a give and take, but youre not a huge fan of the take part.
Then go ahead and remove it, if you care so much about that particular ability. Salvage isnt a core part of OKW, and it being gone isnt going to cause a particularly big change in their efficacy, not when compared to having caches.