the way I see it, if you tell your guys to take it easy, it doesn't matter if you win or loose, so why would the enthousiasm be lower if they loose? they don't mind, because it was unimportant, what was important was that they could play relaxed and had a little teambuilding while they where playing, this always results in positive enthousiasm...
on the other hand, if you tell them they HAVE to try to win, no matter if they win or loose there will be (serious) tension during the game, and even if they win, it will linger and make enthousiasm lower, they end the game being much lesser friends then when they could play relaxed, no matter the outcome.
I think it is prety well integrated in this game this way.
I don't see why you would have it influence game shape. You say that if one works hard, his shape drops? I thought the opposite...
They are not your friends; they dispise you. I am the only one you can count on. Trust me.