For a glider gaggle? that's no problem. Build up interest here, and there's bound to be others who brought theirs along.
For Glider combat? That takes prep, but it's doable.
We'd need to gather gear, set simple rules and have enough interest from here it's worth advertising elsewhere (we're near that critical mass now). The average pilot who just shows up would need to prepare an airframe ahead of time -- not hard, but not spur of the moment -- so they would need to know about it in time . . . and a day's warning might be enough. Something that is announced and talked up Friday, the pilot can pick up a tiny trainer and build in a few hours, and be ready for Saturday morning.
Now is about the right time to start. I'm gonna put up the official/unofficial NASBWACC '15 trash talking thread in a week or two and the glider combat should be about the same, timing wise.
My only concern (and will likely be the pushback) is "too many events". That may not be a concern voiced, but it's something we'll need to consider. Every event we have dilutes others, and shuts down a line or two, usually during prime time. IMO, I think this one is okay, so long as it's a morning event while the lines are just warming up. On Saturday, that's likely even before the pilot's meeting (admittedly, that's late morning).
All that being said, I vote "If you build it, they will come"