Probably because output at 6-pin connector is made for 75W, and output at 8-pin conenctor is made for 150W, no matter how
wiring is done
Hmm so pcie 6pin only have a spider sense haha and the 8pin has two spider sense, thanks for sharing this mate very informative, I hope OP learn from this and don't try something stupid that can probably start a fire, let's respect how these things are built to be on safer side
https://www.gpuminingresources.com/p/psu-cables.html