School Governance has changed massively over the last decade. It now requires a high level of skill in planning, legal, financial and employment matters as well as risk management, health and safety, IT, safeguarding...
It does not require much knowledge of education, pedagogy, assessment practices etc. A bonus if you have someone with that knowledge but not essential.
Any competent BoG should have a regularly updated skills map of their governors, a training and development plan,and a succession plan. The role of the BoG is to ensure that the school is run properly by the people who are paid to run it. The BoG should not get involved in operational management.
In terms of complaints handling the complaint should be handled by a designated investigating team and dealt with by a specially convened panel. An appeal should be heard by governors not involved in any prior stage of the complaint handling. If that can't be done then professional support should be sought from Governor Services (either LA or whoever is contracted) or Governors from another school (if part of a chain or cluster for example).
There is also the opportunity to take a complaint to the Department of Education or Ofsted (depending on what it is) if you disagree with the outcome from the appeal or feel it's not been handled properly.
It's a shit job being a governor and I'm glad I stepped away. It's very hard work if done properly and there's no recompense at all.
And I have performance managed head teachers, dealt with academisation, redeveloped the school premises, overseen a significant budget...no recompense at all