I read that in the Boardgame version,during the course of the game, additional stables can be purchased.
But at the start of the game, do the players own their personal stables (like in the family version) or do they start just as simple bettors? In the first case, if there are 6 players the obvious consequence is that during the game no more stables are available to be purchased from the players.
If you use only the 6 basic Character cards, all the players will start the game with a stable so you won't be able to purchase stables.
However, if you include the "advanced" Character cards, some player may start the game without a stable which will enable the players to buy those stables.