I finally figured out why my $3,- Arduino Nanos from China wouldn't connect the the Mac while they were working just fine on the PC! Turns out they don't have a FTDI chip on the bottom, but use a (apparently cheaper) CH340G chip instead. So all I needed to do was install a driver for those and now they're recognized by the Mac too!
Equipped with this new piece of knowledge you should now be able to figure out which Arduino Nano I had at hand when doing the 3d model for PARTS! :)