The numbers I gave above were so at the conclusion of the Tau War and at the beginning of the war with Gallia.
Additionally, Leeds wasn't under KNF control, at least the southern half of the system, including the planet. The KNF were pushed out of the Taus when the GRN attacked, and their initial attack had no direct consequence for Bretonia. It left the KNF Leeds fleet cut off in Leeds along with the Shogun. They weren't pushed back, but instead left to Kyushu to fight for power by the direction of Newcastle. The remaining Bretonians guarding the system retreated when the Gauls attacked, knowing they couldn't win an open battle.
PS: From what I know, Bretonia lost at least 4 battleships in Tau-31. Those were protecting the Leeds gate, but were disabled in a sudden EMP attack by the KNF, and probably destroyed not much later. At the moment when the KNF had their fugu cut in pieces by rapiers and baguettes, so a year or two after the prior event, the BAF had about 30 battleships total at their disposal, which I stated at the beginning of the post above. I don't know about the KNF, but the Gallic invading fleet numbered 150 battleships.
Weak or very weak, Bretonia is not relying on the strength of its fleet or industry or economy. Simply on the fact that there is no reliable connection between its space and the one controlled by Gallia, and on their allies in Liberty. That might change in case the Gauls manage to establish control over Magellan, both enabling jump gate access to Bretonia and halfly cutting them off from Liberty.