Indeed. The way I suggest dealing with them is to take note of their names and remember to never let them join your clan.
Anyone who thinks about their own stats in a team game is completely out of touch. Team games are about one team winning and one team losing. The least effective member of the winning team still “won,” and the most effective member of the losing team still “lost,” even if that player’s individual stats were the “best.”
Since an individual player by definition cannot win a team game by himself (discounting extreme situations such as a pro beating a team of noobs), the stats of individual players are irrelevant.