According to some senior friends of my staish, Sir Jock runs rings around the other service chiefs and civil servants in meetings. Gen Walker was a decent chap, but we definately need more CDSs of the calibre of Sir Jock and Adm Boyce with a prat like Buff in Whitehall. We've been lucky with our recent CAS chappies - having met Sir Peter Squire I can vouch for his eloquence and leadership. Not met Sir Jock, but he strikes me as the man for the job.
He certainly won't meekly accept whatever the government throws at him, as did Gen Guthrie.