I think it is possible to balance a MOBA 100%. This is because strategies can be used to go against other strategies. While one hero might seem to have a bigger advantage, there is nothing stopping a team from picking around that. What I'm trying to say is that while all matches may not be balanced, this is not because the game is not balanced. It could be due to incorrect choices made by players when it comes to playing and drafting. I'm not talking about Dota being 100% balanced since that is very hard. But theoretically, I don't see why it cannot happen.