In case of defeat, I think we should award 10 points.
In your table, instead of the "% wins" column, you should create a "draws" column. And most importantly, seek support from some authoritative Heroes player, preferably with moderator rights, so that in case of controversial moments, they can act as a judge. And rules, rules, rules. Believe me, these won't just be games, but games for ranking, that is, competitions. Not for money, of course, but still.