Guys, this isn't as crazy as it sounds.
Let me paint you a scenario here... level 260 base, mostly level 15 walls with a few level 16s... Workers are all busy, except one left spare to build walls...
All oil-funded research is being done in the background. No free research slots for two weeks...
Am eating through food & gold, as fast as I can steal it, to upgrade my remaining level 15 walls...
But am currently sitting on 200,000 oil. Heck, I'd be happy to use that oil stockpile to speed up my wall upgrades. So long as it was a choice to use food, gold or oil.
The only risk I could see is if Nexon made it so that the highest level walls were costed in only oil? That's a definite no thanks. But they wouldn't do that.
What am I missing...?