I think it fits the concept rather well, actually, because chivalric warfare works the same way. The knights would have said that it was about having a fair fight, but the fight was intrinsically biased towards them because they designed the rules to benefit their style of fighting.
There is simply no such thing as a truly "fair" fight, because fairness in that context depends on who writes the rules.
And, no, penalising Toshi for implementing the rules wouldn't make the fight "fair", because there is no way to make the penalty fit with the benefit he is gaining. What would make it fair is if both sides could make rules, but then it wouldn't be much of a Reality Marble if it didn't benefit the user....