Sorry if it's come up before, "single character file size limits/targets?"

I’m still pretty green when it comes to blender. Starting to get a grip on some modeling stuff, materials and nodes, and am about to try and make some headway into the rigging/animation front but, I have a question nagging my brain …

Is there any guidelines for “character polycount/file size” I should aim for?
Should there be any targets numbers for overall scene+total character poly counts?
If I i need to get around high counts for “crowded” scenes, I could make super low poly models just to generate rigging and test animation then switch out models for final renders?

Any and all basic animation rules of thumb etc appreciated. Trying to figure out my workflow/pipeline.
trying to get a decent clean “pixarish” look. I assume that means counts are going to be pretty high regardless. Any Zbrush tips in this regard are welcome too.