Some great analysis here. Sorry to get off track, but something occurred to me after reading this.
So far it seems we are assuming that the Federation is only lost territory/space/planets to the Klingons through capture and occupation. I think it is important to consider that possibility that some of the planets or members of the Federation defected to the Klingons. War is arguably just as much about cutting off the enemy's supply lines as it is about battle tactics and firepower. I see no reason this couldn't hold true here.
I'd imagine this to be a serious issue after a few years of war. By year 20 in "Yesterday's Enterprise" it might even be a critical issue by which would be one of the factors for the Federation to forecasting their own surrender.