I'm a fashion shooter (and 5Ds owner), and your quandary is an age old one. The choice has always been "match the clothes" or "pleasing skin tone" since the days of film. Color separators always struggled with that and the chrome type used influenced this. (I was a dedicated Fujifilm shooter, but some clients required I shoot some awful slide film like Kodak EPN which was flat as dog crap and horrible for skin tones but "accurate" for the clothes if you shot it in the studio. The only problem was that I was shooting on location.) In the end, whether shooting film or digital, without extensive work in Photoshop, you can only really achieve "pleasing color".
The short answer is, rarely do they match. And sadly, I've found the last two versions of C1 have offered, well, ugly color. At this point, I've moved back to Lightroom (which has it's own issues), but color is not one, since I can create a custom profile with the X-rite ColorChecker card. From all I've read, the 5Ds is one of the most "accurate" cameras Canon has produced, especially when profiled. I feel Capture One should support the use of the ColorChecker. Others may have different experiences, but those are mine.