Manufactures get to do what ever they want when the designs are submitted to
the testing agencies like UL and CSA. I worked for an electrical
manufacture that ran line and low voltage in the same bundle ty-wrapped
together. As long as you see the acceptance sticker on it chalk it up to
the way of the world.
Check out a electric waterheater. Fed with a minimum of #10 and inside the
manufactures use #12.
Air conditioner condensers are the same situation