It has been my experience that ALEXA and F35 footage has "truer" skin tone reproduction than Epic footage. To me true color reproduction should allow for what is seen by eye on the set to be translated to what is seen on the screen. In order for this to happen a whole lot of technical crap has to happen first. There are steps to the process. Light energy needs to be captured. That energy needs to sampled and then converted (analog to digital) to a numerical value representing the intensity of that energy. This is then scaled into the degree of accuracy of the system: 8-bit 256 values, 10-bit 1024 values, 12-bit 4096 values, and so forth. At this point it is RAW and it can be recorded. This is what the Epic does and what the R3D file represents. But is is not an image. It is not what was seen on set. These numbers need to be crunched, algorithized, transformed, debayered, reborn, interpreted. Debayering is a computational act. It is math. And it does use "real" (discreet), sampled information but it also uses interpretive and calculated (non-discreet) information to turn the math into an image. My experience has been that the accuracy of this process is relative to how the image was discreetly sampled at the sensor. Math can be re-calculated to get slightly better results but math cannot add discreet values that were never present in the first place.
The Epic is an excellent 4K black and white camera. But it's color reproduction I find lacking. The idea that the end user must take on more responsibility and a greater understanding of RED's "mysterious" image-making process is simply silly. Yes, RAW image data can be computationally changed an infinite number of times without (theoretically) destroying the underlining data. But RAW image data cannot "magically" produce chroma resolution that wasn't there (sampled) in the first place. RGB, YUV, XYZ, or ABC do not really matter as they are simply quantitative spaces in which the RAW data will eventually inhabit. Just because I have a 16-bit RAW file or a 10-bit RGB image does not mean that I have all of the luma and chroma information that was originally present in the scene at the time of capture.
I have no interest in which camera system provides bigger and better technical results. My interest is in the system that provides results that are as close to what I see by eye.
BTW: if we say the ALEXA is 4:4:4 at 2K/HD and the EPIC is 20:16:16 at 4K then wouldn't your logic lead us to declare the EPIC is 4:2:2 at 2K/HD?