You'll have to be more clear.
Players' metagaming absolutely can cause an imbalance, as I stated. I've seen a six foot six inch tall, 250 lb. male shout down an entire table of smaller players regarding the distribution of treasure to get the best of the items despite his character being the lowest level, weakest character in the party, and supposedly not interested in wealth or treasure. Clearly a case where player metagaming changed the face of the game.
Whether through bullying or manipulation, greed of a player (rather than a character) often has an influence on how treasure is divided in gaming groups.
As to a DM's choice of treasure, I can see that as well but I'd say it is nearly impossible for treasure ever be available for perfectly equal distribution. So unless you are pointing out an extreme case I'm not so sure I am following your point. Can you elaborate?