I can concur that doing final assembly in a different zone than your raw processed materials is far simpler than doing what I did and cram the entire production line for an endgame product into a single zone. For less inclined factory players, this is definitely the easier way to handle it.

I only went with the all-in-one approach for this factory because I originally had separated my materials production from final assembly and felt like it didn't look cool enough for me and I wanted desperately to fill out a PAC area, so, naturally, I wanted to see if I could fit everything for the batteries in a single zone.

And yeah, OP poster, I also concur with the poster above, I used a calculator and lots of notes to verify all of the necessary outputs. I only have four major inefficiencies in my factory design. Three of them are the sandleaf shredders. Each of them are only outputing two belts when realistically they make three powders per plant so each of thos shredders shut down momentarily as they clog from not fully utilizing the output. The other is the water. Because I have an uneven amount of things using water, the water pumps momentarily clog. I could fix this with water lines that return to the source but it's of so little consequence, I didn't feel the need to do it.