I always thought one of the problems we had was that people couldn't be rewarded for success in a job without leaving it.
If someone is posted into a specific post for 3 years, our career structure generally means they'll be going somewhere else at the end of 3 years. So, they either move to another equivalent job or stir things enough to get noticed, get promoted, and move up to the next rung.
Perhaps if we had a system where someone successful in an SO2 post could be prompoted to Wg Cdr but remain in the same job, we'd have better luck? Man in the job gets his reward, his extra pay, and his promotion, but we get continuity in the post, someone even more experienced (6 years in one job!), and those working under him don't have to run through change as often.
There shouldn't be issues regarding chain of command; if said SO2 becomes a Wg Cdr, he'll still be deputy to an SO1 post. Even if both are the same rank, the SO1 still calls the shots.
Or is that complete madness? There are training squadrons around run by Sqn Ldrs who have Sqn Ldr aircrew on strength; is there any reason why an excellent Sqn Ldr pilot couldn't be promoted to Wg Cdr without needing to leave his Sqn Ldr Flt Cdr job?