The token system is simply the closest model of MC move behaviour that has ever been discovered, and token rules are so accurate that they can be assumed to be correct in at least 70% of gameplay circumstances. While too complicated to explain here, the methods are relatively simple compared to the various mathematical models produced over the years by scientists. For this reason, a full scale token model is generally used for computer MC simulators.
The token notation can be very confusing in its basis - the object of a game of Mornington Crescent is not actually to win tokens, and while the tokens are generally used on the board, they have no points value at the end of the game. The tokens held both by players and stations are simply representations of the status (lateral, on or offside, line velocity, holding targets etc.) of the player/station and the potential moves and plays applicable to them. Again, this is too complicated to explain here, but the entire subject is dealt with in all post-1963 books on the game.