Spud - usually another group of band As are those who have two Bs. I.e. Are homeless and have a disability, or whatever.
I know the system quite well, and I'm afraid it is usually the downsizers that are coming above as you mentioned. And it does seem possible to keep coming third without them lying.
Most band bs wait years in my area, including those with medical problems.
While I do believe people should be rewarded for downsizing to make space, sometimes it's just not right they come above everyone else.
I know people who are severely disabled bidding on bungalows, because they're completely trapped in their current property due to no ramp/level access, unable to reach their kitchen or bathe, who have to wait years because a perfectly healthy person decides to go from a three bed to a two bed.
In our area only those over 65 can bid for bungalows, or people with severe mobility issues. However if you're downsizing, you can bid at any age.
There is a severe, severe shortage of bungalows in the town, so it galls me a heathy 30 year old can take one from disabled people waiting in desperate situations.