I think there was some oversight with having a few players you can verse in these training matches. Once someone realises they can beat you, they play one match after the other against your team, this is not fun at all - why would you want to have someone play you 30 time in an hour and loose a ton of fans.
It also does not make any sense that if you loose a match when someone plays a match against you loose fan points but you do not gain any if you manage to win that match. You're punished if a challenger can beat you and you're not rewarded if the challenger is unsuccessful.
If you win a challenge, the opponent is removed from your worldmap so you can't play a second challenge match against him.
The loss of fans is really low compared to what you can win on a single match. You can win 3 times the fans you lose in a single match, plus a lot of money.