Of course if curses gave 1vp theyd be weaker, but ruins don't give 1vp they give 0vp, so a 2VP difference is not the same as a 1VP difference. If Witch-BM gave curses worth 0vp im willing to bet it'd beat smithy bm,
And I'm willing to bet that it would just barely beat Smithy-BM instead of absolutely wrecking it like it should.
But this isn't about Witch-BM with 0 VP Curses vs. Smithy-BM; this is Witch-BM vs. Cultist-BM. If the game plan is to pile out on Duchies, Ruins, and Curses, then even a 5-3 Duchy split in favor of the Cultist-BM player will not overcome taking all 10 Curses. Heck, even a 6-2 Duchy split just barely puts the Cultist-BM player at a VP advantage.
On another note: played another Dark Ages game today with the WM finalists from Austria and Finland, and Procession makes for sick combos with some of the DA cards. Procession-Fortress gives you +4 actions, +2 cards, a free $5 action, and returns Fortress to your hand (so you can, say, play Procession-Fortress again). Procession-Cultist is great when there are $6 actions: it draws 7 cards and deals out 2 Ruins (though hard to match up, this is great for getting rid of your Cultists after the Ruins are gone).
I'd almost hazard to say that Procession-Fortress is a power combo in any kingdom that has good engine parts at $5; you can just keep on gaining those cards at virtually no penalty, and it gets easier and easier to match them up as you progress in the game.
Knights are swingy and very much a potential liability in a game with cards that have on-trash benefits. Hit Fortress? Free actions for opponent. Hit Hunting Grounds? 3 VP for opponent. Hit Cultist? Opponent starts turn with 8 cards. Opponent has a Market Square in hand? You might trash their Silver; they gain a Gold instead.
(Though I did get the fortune to buy Sir Vander, Procession'd him immediately for a Gold and a Hunting Grounds. Sir Vander is pretty cool.)