I've been in glider syndicates for 25 years based on option 1. It can work fine but gliders normally have only 2 or 3 in the syndicate. Any new partners came from within the club and their characters were known. Some were politely declined.
There's no engine fund of course and not much in the way of depreciation or big periodic overhaul bills.
But then I have heard of a few disastrous glider syndicates as well - with and without formal rules.