One wonders... The Maquis were supposedly a thorn on that side of Cardassia that was facing the UFP. The Klingons supposedly attacked Cardassia from the side that faced Bajor - in theory, they would have plunged right into the home system, then. But there must have been secondary fronts as well. Did the Klingons perhaps drive Cardassians away from those areas of space where the Maquis operated? Or did the Klingons avoid those areas because of the high probability of pissing off the UFP there? Perhaps the Klingons even calculated that they needn't bother with the Maquis-infested areas because the Maquis were already doing such a good job there, tying down valuable Cardassian resources in missions of secondary import.
Certainly just the fact that the Klingons wounded the Cardassian military and cut some Cardassian supply lines would be of great help to the Maquis, no doubt. Thus, the Maquis might have felt they needed to repay a debt by doing some favors in return. Or that's what I'd have done if I were Maquis: the way Klingons think, they would then feel indebted to do counterfavors eventually.
Timo Saloniemi