I think Tunnel is too slow, Jack/BM with Hoard and potentially a Feodum buy early on seems better, Hamlet is really nice with Jack and I think you buy it over the Silver after the turn 3/4 shuffle.
Well, what I would actually do is open Jack/Develop and do Develop shenanigans, but that may be slower. Silver -> Jack + Hamlet is very nice. Develop - Feodum is of course always nice, and with both Jack and Develop it's more reasonable to pick it up for the on trash. You can also use it as a source of Copper trashing which decreases hand size for a Jack-based semi-engine (I say semi-engine because you won't have time to build as much, but you should be able to get better cycling with similar money output to Jack-BM)
Other fun Develop tricks here are Develop a $4 into Cartographer + Tunnel, then play either a Jack or a Cartographer to discard the Tunnel, Develop an Inn to shuffle actions in during your turn, Develop $4 into Duchy + Tunnel late game...I don't care if it's potentially slower, not exploring all the Develop tricks you can do on this board is a travesty. There's an argument for either Jack/Hamlet or Jack/Develop if you go this route, I'm not actually sure which I like better.