Not fast enough for the Borg, I fear.
Ramming your ships into Borg vessels is not a good way to keep your fleet up.
From the maps of the dominion seem to have thousands of worlds.
Now if only a handfull of third rate cardasian worlds can produce enough ships to bring the federation to its knees think of what a vast empire that is most likley 3 times the size of the federation and has had thousands of years to build its shipywards and military industrial complex? To me invading the dominion would be like kicking a wasps nest.
Resistance in this case would be far from futile.