I've always heard that command stars was related to the king's influence, not command. Usually they will both be high or low, so it might be the one or the other. Makes sense for the other stats to track the king's.

In the unit_prod file, column 10 is "General Candidate?", with Preferred, OK, or Discouraged as the options. Most cavalry units are Preferred, missiles and peasants are Discouraged, and infantry a mix of all three depending on quality. I've got two guesses on this column, 1) that this affects the command rating of the unit leader combined with the Influence/Command of the king, or 2) this determines if the unit leader will be a Noble (Sir).