One person does something it is legal, but if N people do it it is illegal? I do not think that is what you are trying to say, but I can not isolate what you are trying to say.
Unlawful assembly, at least as it usually is defined in the US state laws (the British form has been expressly repealed for decades, and so isn't an offense in any case) requires not only a purpose of disturbing the peace but the completion of some offense, and so would be illegal in the N=1 case as well, not only in the N>>1 (or even just N>1) case.
So, while there may be a good point here, that's not a good example at all.
I thought about that example specifically and it does not seem to fit.
Normally the problem with too many people assembling is that they they block businesses, road ways, etc. In this case each person is not doing the same thing as when N=1. Some N+1 person comes along and decides that it is ok to block a door way or a road, or can not tell that their addition adds to an egress problem if there is a fire. In the example of unlawful assembly of N>>! people are not taking the same actions as when N=1.
1. Marrying one person is legal. Marrying >1 person is not.
2. An S corporation can have at most 100 share holders.
3. Zoning limits on the number of people that may occupy a structure are common.
> Just because a single instance of an activity is legal does not necessarily mean that N instances of the same activity are legal.
> 1. Marrying > 1 person
Is not n instances of marriage under the same conditions. It seems like to fit your original statement it would have to be that one couple marrying was legal while N couples marrying was illegal.
> 2. An S corporation can have at most 100 share holders.
The number of people is changing but it is only one instance of forming a S corporation not N instances of forming an S corporation.
> Zoning limits on the number of people that may occupy a structure are common.
The N+1 person moving in is not really doing the same things as the first person moving in similarly to the unlawful assembly.
It would be interesting to look at laws implement actions which are legal with 1 instance but illegal with N, but the example you have quoted so far to do seem to have any carry over to the Aero case.