Averages or best 18 is so crap... No chance of big name players tanking, no chance of lesser likes going big. Part of the fun (and frustration) of SC is being randomly blessed / torched by circumstances out of your control. Zero (DNP) would be the fairest option and would make people cover with their bench. I really hate when good planning (ie having cover in case of unforseen circumstances) is trumped by "fairness" or "making people happy".
IMO a best 18 scenario is the worst result. Absolutely saves people even if they aren't impacted by the cats / crows game.