John Stott on Acts 6:5-6

In his book Living Church John Stott writes regarding Acts 6:5-6:

A vital principle is embedded in this incident, which the church urgently needs to re-learn in every generation, namely that “everybody cannot do everything.”  Indeed, everybody is not called to do everything.  Or let me express this principle in three positive statements:

  1. God calls all his people to ministry (diakonia).
  2. God calls different people to different ministries.
  3. God expects those called to the ministry of the word to concentrate on their calling and on no accunt to allow themselves to be distracted by social administration. 

So, I have a question, how do you all think about his last point?  Are there some called to the ministry of the word and that if they are that should be their only focus?  This basically affirms the role of the preaching pastor/elder and that others could or should focus on the social ministries of the church so the teachers can focus on theirs. 

What say you?