S'funny, I checked the Haddon-Cave website after my last post and I saw the bit about Ness being an advisor as well (for the first time). I don't think Ness has been long in his current MoD post but I don't know how long he's been an advisor to HC. It doesn't feel quite right to me, either.
Incidentally, Baber's move was done at short notice and without a planned succession. Doesn't sound like a normal end of tour to me.