There is one other possible way of doing it, and that would be to have the steering committee meet after some work by the staff, on the lines of questioning the committee might want to take. Then the steering committee would decide how those questions are going to be divided among members and try to encourage members of their parties to adhere to that.
I would like to make one comment in response to Monsieur Nadeau's comment that sometimes the water is muddy. Stephen Leacock, who was a great Canadian political scientist, once referred to one of his colleagues and said that every time he lit the lamp of learning he filled the room with smoke.