That must be disappointing. But sometimes we just have to make the best of a situation that presents itself. So have you had a great 101 experience with the one guy who showed up? TYWe hosted a gangbang and 1 out of 13 guys showed up. I will give a second chance as long as it wasn't a no call no show.
i think a lot of an arrangement being successful or not depends on where you are looking for people to play with. Swinger platforms that have some sort of verification process are typically a better source than dating ad platforms. And preferably go for guys who already have some experience in whatever sort of "sex dating" (swinging, hotwifing, etc.). Newbies are more likely to get nervous and flake.
A GB is a very special type of arrangement. Not every guy is comfortable with a bunch of other guys around; some may be overwhelmed by the idea of having sex with a gorgeous lady like you but then catch on second thoughts. It is more likely for a guy to show up, if he has been part of a gangbang before, or at least a MFM, and enjoyed it. Be upfront about what you expect (e.g. STI/STD testing; will filming or taking photos be allowed or even requested?), discuss it and agree on "ground rules" before an invitation. And plan ahead of time!
Good luck.