They started a war between the Cardassians and Klingons, no?At this point I'm wondering whether the Founders even really cared whether or not the Federation and Tzenkethi went to war, or whether it was more of a test. We never see the Dominion engage in this particular tactic again, and it is arguably a little inconsistent with their normal methods of handling situation.
It's probably safe to assume that having Krajensky get killed wasn't part of the plan though.