I've been to visit a school as a prospective school business manager.
It's a tiny (35 staff) infant school with a separate junior school sharing the site. The junior school has it's own business manager.
It is very likely that if one of the heads leaves, the schools will merge. The infant head has been there 15 years, the junior head 2 years. If the schools merged there would only be one SBM and whilst in theory it the selection would be based on performance/skills, in practise I imagine the remaining head would keep "their" SBM (unless they would be glad to see the back of them!)
I loved the school, the job and location is perfect for me, the people I met seemed fab, but....
ATM I have an OK job, I don't hate going to work, but it is time I moved on and took on a new challenge. This would also be enough extra money to make a difference to us. WWYD?