I have to agree with some of the sentiment here. It is in the presentation sheer numbers can pose an epic challenge, explosives in sufficient quantities, one high power spirit, full auto from a hvy weapon etc.
I've rated my home games in 4 grades 1-3(Novice)/ 4-6(Vet)/ 7-9(Prime)/10-12(Welcome to Z-O) I use this for Spirit force,program maxes,initiate grades etc.