to people who know stats, would allies having basically 50% more players due to having 1 more faction always skew the winrate for allies? as said in the article, if one side has more players, that side would not have enough counterparts on the opposite side.
I'd say no. Thing is, in order to play a game you have to have an allied player and an axis player. Like, you can't have more games on allied side than on axis side in total. If there really are more players on allied side, it means they have to wait longer for an axis player to become available so effectively the fewer axis players play more games in the same time.
Now, what may happen is that people in certain skill ranges play more or less games for a certain side. Assume VonIvan is the only player on axis side, and I and I2 would be the only player on allied side. In that case, Von plays twice and wins both and I and I2 would loose. So axis would have a 100% win rate.
In coh2charts this would look like axis has two games in the 1-250 bracket and a 100% win rate, and allies would have 2 games in the 500+ bracket and a 0% win rate.
So, generally, if more good players play on one side, they would eventually be matched with worse players from the other side, which in turn would result in a higher win rate for the first side. The correlation of excess players on the allied side in 1-250 bracket vs. winrate that is mentioned in the post could be an indication of that.
But again this should be independent of the number of factions. If all UKF games would be played by guys like me, axis winrates in the 1-250 bracket would go up. If UKF would be played only by Hans, axis winrates would go down.
Now, if you think about team games: Not sure. The general mechanic will still be the same, like when one side has better players, it will result in higher winrates, obviously. However, in team games it is less straight forward as the matchmaking has to create teams of equal skill, which I figure is very tricky.
Less players means that the pool of players that matchmaking can pick from is smaller. This might be both good and bad, depending on how good the assumptions behind the matchmaking algorithm are....