It was always my understanding that quad tournaments are divided up with an eye toward minimizing rating ranges within the quads. This (hopefully) lets everyone play against people of roughly the same skill level, (again, hopefully) leading to well matched games throughout the whole tournament for everyone playing. This is done by taking the top four highest rated players and putting them into one group, the next four highest rate players into another group, and so forth. I understood that unrated players would be put into the lowest group, although I didn't know what would happen if there were a lot of unrated players. However, I had never played in a quad until fairly recently.
In the quad tournament in which I played, the top four players were put into a single quad. However, the other quads were not clustered together by rating. In looking at the cross tables, I see that there were several quads with 400+ point ranges in rating, even though the distribution across the tournament would have allowed most quads to have ranges of 100 points or less. Admittedly, over 25% of the players were unrated which would have meant multiple quads of unrated players if they had been grouped that way. Instead, there were one or two unrated players per quad (other than the top one).
Is this sort of grouping for a quad tournament allowed? Normal? Abnormal?