EXACTLY,,,,,,, I agree. Theres less voltage drop and less I Squared R heat loss in a bigger cable, Ohms Law still applies and thats indeed an inescapable engineering fact. HOWEVER, as starter current increases over ideal conditions (engine problems or starter problems or common and typical connection problems or colder temps etc) then voltage drop becomes much more and more critical. PROBLEM IS if you go wayyyyyyy too big then the connectors and terminations and attachments become troublesome.
If a tractor starts fine in cold temps with X size stock cable (Like Rustys) no need to go bigger but if there are problems due to excess voltage drop, then as you stated, bigger is better (subject to limitations above). Im NOT one of the Correct Police who pick and judge other peoples work so if people like pure stock Im happy but if they choose to go with improvements its their tractor and their money and their choice and NOT ours so I dont come down on people who use stock ORRRRRRR who use improved products
Thanks gang, fun chat for us sparkies and hope we helped and didnt bore the others lol
Best wishes n God Bless yall