The matchmaker of World of Tanks has been changed several times over the years, and in a developer's diary further changes were announced. Since patch 1.4 I have installed a new mod pack, and one of the features is calculating a "win chance" from the WN8 scores of the players on both side. And however flawed using WN8 or Wargaming's own WGR score might be, that "win chance" indicator clearly shows two things: That a) when a large imbalance exists, the side with the "better" players is extremely likely to win, and b) the matchmaker doesn't appear to include any of those skill scores, not even their own.

I do wonder in how far that is working as intended. Extremely unbalanced games are very fast, don't block much time for the losers, and are quick fun for the winners. More balanced games take a lot longer. Of course more balanced games can be more nail-bitingly exciting, at least for those tanks that survive long.

In general the problem with matchmaking algorithms is that the more conditions you introduce, the longer people have to wait in a queue to play. However the addition of the WGR score to match balancing would be easy enough: The current matchmaker already gives you two lists of equivalent tanks, and one could just switch a few tanks from one team to another to balance the skill better. I think that would make the game somewhat better.