yet those major changes haven't altered the track of history in England/France at all, such that not only is there still a Napoleonic war but all the major players seem to be the same

Yeah, I always have to turn the nitpicky part of my brain off while reading alternate-universe stuff, because it just doesn't make sense for some things to be so different while others remain exactly the same. I'm willing to go along for the ride here, though, because I like these books so much.

If you love Temeraire, then you'll really like the latest novel in the series, Victory of Eagles, which has a whole, long, wonderful Temeraire POV section.