When a team is functioning, everyone is pushing together in the same direction.
There is a great expression for this in English:
"Put your shoulder to the wheel"
In comparison, a dysfunctional team is pulling apart. Disagreement in a team is healthy, but when a decision is made, everyone needs to get behind it, otherwise a team can start to pull in different directions, which is obviously dangerous and leaders need to work to prevent this.
Imagine a boat with everyone rowing at a different tempo, and you can see why this cannot work for any length of time.