Job families in DGs

Hi everybody!
For some units the Commission Directory lists a lot of positions called "Programme Manager - External Relations". Does this mean that the job family of external relations is very present in this unit and an application for other job families for this specific unit probably will be less successful?

Clicking through the directory, I found some sub-units which lead to a kind of dead end: they list simply the cell's name but no employees. What does this mean?

Thanks!