>>539238530
I've seen people quote different coin drop numbers which make 13-4 or 14-4 look better depending on which you use. I don't care to test it... but those two are close in coins/oil ratio, and are a step above the rest.

15-4 does give more coins, but costs 490 oil while 14-4 costs 401 and 13-4 costs 392. Its ratio isn't even as good as 12-4's.

I think it makes the most sense to farm 12-4 until you've leveled up every ship in the game. Its coins/oil ratio is 87-88% as good as the max.

>>538446030
It's hard to think of a circumstance in which I'd need medals more than coins, and you get coins by farming 12-4 with full fleets.