I remember a guest on stage asking after the local floor talent who then had to be rustled up as the plan had been the support band (albeit local).

As mg says its up to the organisers. Pick where suits you. I prefer floor singers but I've also seen a guest go home after a very short second set as the mc had tried to fit in every floor singer.

Another dilemma; when the guest attracts good floor singers who don't normally visit - do you put them on or the faithful regulars?