I suspect a lot of attempting to not become a Hirogen trophy, mixed with not giving replicators to the Kazon, combined with a fair bit of running away from Undine, all of this while trying not to be assimilated.
The old ships showing up in DS9 was also due to desperation during the dominion war and simply pulling the old ships out of mothballs with some basic upgrades was the fastest way for the federation to build up their fleet size. Jem'hadar ships were not particularly powerful on an individual basis, and the dominion relied…