What is the maximum or ideal amount of characters that should be given equal amounts of screen time and character development?
For a one cour series, I'd say five tops. Less if you really want to focus on getting to know them and developing them.
https://en.wikipedia.org/wiki/Rule_of_three_(writing)
>>158891616
I'm no specialist, but I know that guys like Eisenstein proposed some other types of "montage".
So I'll just assume it depends on many factors, but if you're going with the traditional Occidental inherited style, I'd say 3 is the most you can bear.