Not quite true Stillalbatross. Don't forget about our colleagues who have the seniority for command, but are not in the left set.
A wicked combination of Cat B, C & D FOs, many in VERY dubious circumstances, and some guys who've decided to stay on bases, rather than return to HK for command - mostly a lifestyle & financial decision, proving that the "premium for living in HK" is a myth.
Look around, you'll be surprised at the number of people out there in these categories, and then ask how many current captains suffered the indignity of a delayed command - usually a big dose of intimidation to make them "appreciate their jobs"