Rats, Forager, Fortress
4-3 Split: Open Rats, Forager (or silver and buy forager after first reshuffle)
Rats eats coppers and estates/shelters
Forager eats rats giving at least plus one $ along with an action, a card (from the rats effect) and a plus buy to get more foragers
When the rats run out of coppers and estates buy a fortress (a village returns to your hand after trashed). they can gnaw and breed all they like, they won't gnaw through the fortress, meanwhile foragers get more and more powerful as different treasures are trashed (cheap alternative treasure in the kingdom would really help too, like loans and fools gold)
Also, rats and death cart seems like a match made in hell