The Klingon fleet lost a ship to the Feds at system one, but held off light Federation assalts whil constructing a shipyard. Right now a ship is being repaired before they move on toward open space. I'm going to attempt to make it through without building more ships. If the balance is still way off I'll change my mind. One interesting note. The ship being repaired during combat obviously can't fight, and if the shipyard is destroyed, the ship inside of it goes along with it.