My old club held 2 every year. It was 3 + putter and I would always carry 6, 9 and 52*.
At my mates stag weekend we turned one of the rounds in to a 3 club on a really long championship course and I did the same combo which I regretted, should have been H17*, 7 and PW that time.
Played one once and it was fun - used 7 wood, 9 iron and putter
if i were to do it again - driver, 5 iron and PW - simply because i can hit a driver off the deck - and its a good putting club!
Depending on whether the comp is 3 club + putter in which case 5W, 6iron and wedge (plus putter) or strictly three clubs then 3H, 7 iron and wedge and putt with hybrid