I don't think for one minute that this website needs the organisation of CAL as an excuse for a bucket load of more arguing.
Anyway, in my naive and blissful ignorance I will take the question at face value and give an honest answer.
It was decided at the outset that the ideal number of directors would be about 3, I personally favour an odd number for obvious reasons
The company was formed by Stuart France and me, who being the original subscribers and guarantors for a company limited by guarantee are the owners of company as long as we live.
Dave Tyson was asked to join us after formation.
In the event that one of us falls by the wayside there will be a need for replacement in which case the remainder of the board would ask someone of reasonable qualification and who was willing to participate in the dark conspiracy of maintaining a policy of free and open access to the mines we control.
Seconds out
Addendum
Just advised by the website that there has been 3 postings while I was typing this out, no comment.