The Trasmute- Duke idea is interesting, though. If there were better $4s that you could have floating around in your deck...
Jack should be reasonably good support for Duke, right? And look, it's a situation where Scout is not entirely useless!
So I was thinking about that -- I came to the conclusion that Jack isn't as good as it first appears. Lots of them certainly aren't.
You want to try to play Transmute every turn and also buy MS or Duke/Duchy, so you can't have a bunch of Jacks floating around. One, maybe. And you can probably use it a couple times if you don't draw a Transmute. But when should you pick it up? Open with it? But you probably want Potion ASAP to get your first Transmute. Second shuffle? But you need more market squares, too. Silver's great to hit $5, but it also reduces your chance of SM Gold into green x2 which seems kind of important.
Scout might actually be better because the +1 Action is actually a big deal and you are going to have green floating around... but better than more Market Squares and enough in time to make the Governor player think twice before a mega-turn? I don't know....
A second Potion might actually be better, first. A Scout or two. Maybe a Jack? I guess that's a sizable number of $4s. But is getting them going to slow you down too much?
I guess I don't really have a good feel for this.