In danger of complicating things ar'nt we.
Keep it easy.
Agree up front three venues will be fished.
Agree number of matches - either 4/4/4 or 6/3/3 or whatever.
Then agree venue with most votes is 1st venue, second highest second venue etc
My ending to questions / concerns is all that needs to Happen. Its Mark's league, just grow a pair of man balls and say where its going by making a decision. If some don't want to join then that's their choice, whatever happens it wont please everyone and by doing what I intended it just becomes a joke and still wont please everybody. Keep it simple, pick whatever venues he wants / can get / cheapest or whatever, tell everyone before they join then they can make their own mind up, nothing any easier than that Could do with a few pair crappity smack off anyway because they do what they want and that's out of order, if you don't want to commit to and fish a league don't join one