Maybe Sony is doing less control than Canon in body and that is why Sony is more "ISO Invariant".

From the link in your last post:

"How does the 5D Mark IV stack up against some of its other peers? Its performance is much better than any other offering from Canon, but it's still not quite as ISO-invariant as the Nikon D810 or D750,"

Perhaps Sony has given the illusion that its ability to handle DR is greater than it actually is.


This quote, it really is another version of the DR discussion just said in a different way with different terms.

The 5D Mark IV isn't entirely ISO-invariant: pushing an ISO 200 underexposed by 5 stops by 5 EV in post-processing yields slightly higher noise levels than a native ISO 6400 exposure. An ISO 100 exposure pushed 6 stops fares even worse. However, above ISO 400, the camera does, for the most part, exhibit ISO invariance, meaning that you could underexpose a traditional ISO 6400 exposure by 4 EV by shooting it at ISO 400 (while maintaining the shutter speed and aperture for ISO 6400), and then raise exposure 4 EV in post. This technique would afford you 4 EV of highlight headroom, with little to no noise cost, relative to shooting at ISO 6400.