I totally argree with the answer above. We need more context here. It could be that members of this team are so good in what they are doing that they are so successful. It could also mean that opponents of this team are causing them troubles, because they are better than them in the lets say, same type of business. Therefore rocking could have negative meaning.

Sometimes, the work rock can mean to move back and forth slowly. "The mother rocked her baby to sleep". Look up a 'rocking chair' . However in the case of "rocking the sales team" it is not so clearly defined. English uses the phrase "rocked your world". This means something happened that changed your whole life. In your sentence, they are rocking the sales team by winning in some way (I think, I need more context really). Rocking can mean doing something very well. Sorry this wasn't very clear, the word does not have much of a clear definition