This is a beautiful set, really. I've given it some more thought and no simple approach whatsoever works.
I would have gone Explorer first. Maybe just Explorer+BM? There isn't much on this board, but the Silvers from Explorer would pretty much defend against Saboteur. Add a monument for some vp chips too. I think Saboteur will kill engines, since there's no way to really defend. It'll hit all your components.
You would lose to the decks we were building. Wandering Minstrels, Monuments, and an Apprentice to do some cleaning. I don't buy any Saboteur against this deck. If the apprentice ever runs out of fuel I could add a noble brigand but that's not even necessary. You just can't buy enough provinces to fight the ever going 3-4 points a turn from the monuments. If you buy a Saboteur in your BM deck, I just ignore it and re-buy lost components. You can't play it frequently anyway.
I think I would mostly ignore Sab and just keep buying Minstrels, Bandit Campus, and Monuments. Lots of each. When they get hit, I turn them into Vagrants, and we look toward a three-pile. A bunch of Saboteurs will hurt me, but I accumulate Monument points while he doesn't. And he can be buying like tons of points with just Saboteurs.
Again I would do what we were doing in the actual game. But now I add exactly 1 Saboteur. Then I just keep buying wandering minstrels and monuments again. Basically we're playing the same deck, but you're steadily losing components.
Besides, Apprentice allows for some pseudo-draw, maybe with the Silvers from Explorer?
Although that seems really convoluted.
Silvers from Explorer can come in handy, but if I'm fighting BM I'd rather use the silvers from Noble Brigand.
It's a kingdom that you could win with a 5 card deck.
edit- actually the noble brigand can always give you a fatal sixth card.
What 5 cards were you referring to? I guess you could try with a village, two monuments and an Apprentice. You can trash the incoming copper and continue to score 2 points/turn. But 2 points isn't really that much and you can't quickly switch to something that punishes a fat deck with green cards.