In one of the very first runs I was in with the group we had a similar problem where I believe a few didn't make the run at all because we had too few for two full loads of eight, yet too many for a load of eight and a reasonable number for a second load. At least I at the time, and I think maybe some others, weren't sure of everybody else's comfort level as far as loading 'short' and if I remember correctly, there weren't alot of toons who were able to communicate with each other on the platform. A few of us came back after the first run to try for a second run, but the ones who didn't make it had gone (understandably).
After that happened and some discussion here, I understood that if we didn't have enough for two full loads of eight, we'd split equally. If we had 12, we'd split 6/6, 11 then 6/5, 10 then 5/5, subject to each person's comfort level. Steve posted guidelines afterward allowing for the suggested number of people for each Boss along with the ability to opt out at one's own discretion. He also included tips for battling with a 'short' load which I think are excellent.
A.T.T.A.: Boss Battle Runs
This past Saturday and Sunday evening were the first runs I've made in a couple of weeks due to Boss, but I recall everyone easily following the suggested guidelines on the runs I've attended without any perceived problems. I think in Saturday's CFO we somewhat agreed to split 7 and 7, and if I recall correctly I got off the first elevator to even the load and a little 'shuffle' occurred, but then it was fine. In Sunday's CEO a few stayed back because we had 11 or 12 I think, and in the CFO that followed we had too few for 2 full loads of 8, yet if the first load would have gone with 8, some would have been left back. We had enough offering to stay back so that a full load of 8 could go, and we had enough offering to go 'short'. I think I heard a couple of challenges to go in groups of 4 (I loved Margaret's acceptance of the 4-person challenge on YIM - I wish I could remember it verbatim to put it here).
Ultimately, we ended up waiting for some toons that I think others called to join us. The first load went with 6 and I think I heard the second with 8. There seemed to be alot of confusion or discussion over who would load with whom, but I believe we initially had enough to go at least 5 and 5 if all were willing, and I'm certain there were a couple that would have gone with 4, myself included, easily (and at our own risk!).
It's alot of fun having the ability to communicate with each other outside of the ordinary Toontown methods, but if the regularly scheduled runs are intended to be open to all even for purposes of attracting new members, I'm speculating not everyone will have the abilility to communicate with everyone else outside of Toontown's methods at least at first.
To avoid delays, confusion, and frustration, I might suggest the group consider adopting the guidelines in Steve's thread as "official" and let's just 'load and go' and have some fun. As the group grows, I'd imagine eventually the options of loading 'short' or opting out would fall on the last 2 or even 3 groups to go or late arrivals. The guidelines are excellent and reasonable, a schedule of runs are included, and I don't think it's unreasonable to expect that members and non-members alike would or should have read them prior to attending any of the scheduled runs.
Those are my thoughts on the subject.