Painting model cars is different from painting flat armor or doing little detail squirts etc. You need a good hefty flow of paint and broad coverage on most car bodies and of course you want the shine which means good overlapping patterns. And you want the paint to flow out.
I don't agree 100% with everything said in this video ( like jar size for instance) but just watch and look at the result ( you might have to copy the link): https://youtu.be/lCKZ_fo4eW0
In the video it was mentioned that he uses the #3 needle set, fwiw that is a .77 on the Paasche H. He also mentioned that this was a Don Yotes technique, well Don was never alone on that ! But Don has won more model contests with his paint work than most of us have built models, never mind enter them in contests at all. Not that I'm advocating the Paasche H exclusively but Don does. I have one but mostly use my 40+ yo Badger 200. But the point is you need the tool you need and not because the tool is pretty looking.