My local wat recently had a power struggle, and the governance went from 95% Board, to 100% Head Monk. This made the both laypeople and monks happy. Everyone was happy except the board members, who resigned.
Now there's a new board to advise the Ajahn, who makes the final decisions. Now it seems to work well.
Here's a model which is more equal:
This is the Charter of Santi Forest Monastery near Sydney. http://santifm.org/santi/wp-content/uploads/2010/09/sfmi-constitution-10.08.pdf
A lot of thought has gone into the writing of this, so it's a good read.
Basically, a Spiritual Director is nominated by the Sangha, then further accepted by the Board.
If the board rejects the Spritual Director, the matter goes back to the Sangha.
If there is a deadlock, the matter is referred to an external body for mediation.
The board is elected by a vote of the members of the wat association.
The Spiritual Director has power of veto.