Sooner or later, maybe sooner, we are going to be asked this question. We need some answers.
Here's a suggestion:
Instead of getting bigger and bigger, we should be getting smaller and smaller, maybe under a central federal system, like the USA with their states.
We could have a dozen HAs with around 3,000 in each, run by a sub-board which would be largely self determining but not entirely so. Some of these mini HAs would get a better reputation and residents could migrate from one to another.
The now defunct West Hampstead HA was at its best when there were around 1,000 people.