I doubt that Rats/Upgrade is the best strategy here. It sure worked out nicely for you, but only because your opponent went for Rats as well. Emptying the Rats pile alone would take considerably longer. Note that all your opponent needs to beat your strategy is 2 Colonies and a Duchy (23 points vs 7*3=21 points from your Duchies). That should be possible before you can end the game. Once you lost that race, there's no way of coming back.
That said, if there ever was a board where your strategy might be viable, it's this one. So incredibly weak, and a BM player gets stopped by Militia. Getting Madmen and Forge to trash all your bad stuff at once might be a thing, but is also dangerous due to the presence of Militia. I'd probably just go Spice Merchant/Silver or Militia/Silver (Spice Merchant if I see you open Rats), some Upgrades, one or two Militias, and money.