It seems to me there is a relative limit for commercial fiction regarding the number of named characters. This makes sense, of course. Readers get confused; lots of people aren't good with names.
Fantasy novels, or other fiction with an adventuring party, might have 6-10 protagonists, but the antagonists are frequently unnamed squash victims.
Series, and epics cut into trilogies, might build up characters over time. But there are a lot of pages to fill, and the reader will have invested dozens of hours.
So I'm curious if anyone knows of any "behavioral science" on the subject, or if you just want to express an opinion.
Thus, perhaps something like Fifteen named characters per 100,000 words ...