Think about it logically, if a team has an overall better teamwork rating then they're going to work better as a team, which would effect things like runs, positioning of defenders and attackers, first time passes and the like. If you want a really simple (but time consiming) way to tell try playing a game with a club like Chelsea on exhibiton where they'll all have 80 something teamwork, then start an orginial team master league, but all their players at the selection stage and see how much worse they play.
My centrebacks, fullbacks and D mids on ML mode have 90 + something, with dmf both have covering stats, so if one defender leaves his position the dmf is there befote you notice, makes defending a bit easier.