Remember that Information bases that use the Hermitage wonder can load another museum artifact of their choosing. For a while, I had one that gave another 50% all resources looted. Then there are the Pay2win Museum artifacts that can boost looting, plus a blessing plus British, etc.
So yeah, you can jack up your all resources looted crazy high.
Personally I've STOPPED doing that. Earning 50 or 60k oil per battle sounds good in theory, until you are constantly full of oil. Instead, I swapped in artifacts that gave more boosts to my bombers HP.