New Year's Duel Tournaments. Regulations, Rules.

How about 3 games? The first one is random, the second one is also random, and the third one is a mirror match of the second? What do you think?

3 games is fine – Heroes is a game where there shouldn't be any draws; we play until someone wins. Regarding the random element, it wouldn't be fair, as someone might get lucky in the first random game, and the second and third games being mirror matches increases the likelihood of a draw...
In my opinion, it would be more logical if, if we can't avoid random elements, we have one random game, the second is a mirror match, and the third is a standard game.