the beatsnap divisor is based on how many sounds are between each beat of the music (subdivisions).
different songs use different snaps, some use multiple. most music just uses either 1/4 or 1/3 (or their subdivisions 1/8 and 1/6) with 1/4 being the overwhelming majority.
So its entirely dependent on the song they chose. mania mappers just happen to pick songs with polyrhythms and/or multiple kinds of rare subdivisions pretty often as they can make interesting charts.
I assume by sorted map you mean ranked? if so as long as the music actually uses the subdivisions you chose, or you can give a good enough explanation as to why you use a differing snap (unlikely most of the time though) it can and has been ranked.