if you look at the timeline, When the Jem Hadar attacked the Odyssey, they kicked the Galaxy Class Ship handily...
They didn't, really, which was why they did the kamikaze. We can never know if the Bug Ships with their weapons alone could have destroyed the Odysey. It was limping away but it
was limping away and it had plenty of unfired torpedoes.
...
The Dominion did in fact have Shipyards going in the Alpha Quadrant, mostly in Cardassian Space.
The current debate is, if the Dominion's true power was in the number of ships, where did they get the resources for the ships during the prolonged conflict. If they brought it with them, by the time Starfleet retook DS9, they were falling back. Yet, later, the Federation was losing the war. Cardassia couldn't supply the Dominion anything because they had to occupy Bajor for the ships they had currently. It makes more sense that the Dominion's true power was in their tactics, namely infiltration, covertly ordering fleets to patrol useless positions, luring ships and convoys into ambushes, or simply having a single Founder board a flag ship as an engineer to blow up its warp core.
... Insurrection, and later background dialog showed that the Son'a were making Ketralsel White for the Dominion...
That explains the soldiers, not the ships.