Why is Boris recruiting press officers?

The Mayor of London already has at least a dozen press officers. I understand the total is 15 - down from 16 under Ken Livingstone. This is just to handle the Mayor's press enquiries - The London Assembly, TfL, the LDA, etc, etc, have their own press officers. Most are still in place from the Livingstone era - although Joe Derret, who used to be the London Labour Party's press officer has now stopped what he must have found a curious role promoting Boris and instead gone to work for Waltham Forest Council.

I doubt the Mayor's press office makes much difference to the amount of coverage Boris gets or that they have much success controlling what he says. In any event there are far too many of them. Making people redundant is expensive as well as unpleasant. But why are they still recruiting? 

Top tip. You can cut back on staffing numbers rather a lot by simply. not recruiting replacements for people who leave.