Austerlitz & Leipzig are being played with the Blucher rules
The C&C games are more clearly C&C b/c of the use of cards to drive the action each turn
There's also a set of rules called "Snappy Nappy" that (IIRC) are a little higher-echelon than Blucher
There have been others that Jim's dabbled with, like Sharps Practice, but I think those are lower echelon.
The old SPI quads were clearly using the rules for those specific hex-and-counter games
So yeah, there's a bunch of different rules being played, depending on which game you're watching.
Tonight's Austerlitz game is using Blucher