How "mothballing" aircraft helps profitability I cannot tell you. Unless you are running them at a loss that is.
Insurance and maintenance checks still need to be paid for, the only difference is that you have no revenue at all to pay for them.
From my point of view as someone who's been involved with running clubs and schools, the Sherburn committee sound incompetent. Either close the club or run it properly. Anything in the middle will just ensure the death of the club eventually.
Closing one day a week in the summer..................You what? Madness.
"Mothballing" the fleet? Even worse.
I hate to say it, but if the club are still in business in two years. I'll be surprised. That would be a tragedy. To lose a club with the history of Sherburn would be a terrible loss to the industry as well as the members.