“Towards the end of the last Mortal Kombat, we’d been talking about fighting tournaments such as EVO,” says Boon. “Those who participate and attend tournaments are always talking about matchups;
“To make it a competitive match, you have to change characters. But people don’t want to stop playing with their favorite characters. They would say, ‘I love Sub-Zero and I don’t want to play with anyone except Sub-Zero.’ So we said, ‘Let’s make a version of Sub-Zero that plays differently and has different strategies.’ And that escalated to making different versions for every character. That ultimately led to each character having three play styles."
-From the gamesradar.com article with Ed Boon
After reading that article and reading the comments from colt, it seems like the dev's wanted people to be able to change characters after any match to get the best gameplay out of both players. Maybe the best coarse of action is not to make any rules at this time and let people use skill to determine who is the best player.