I really hate that chart :\ It's a good effort, and maybe a good CMYK match from the brochures, but there are so many colors that aren't even close.
For instance, they VMC Scarlet Red looks nothing like Citadel Troll Slayer Orange (By the way, why does Vallejo hate us and make a Scarlet in the Game range and Scarlet in the Model range, that are different colors...). They equate Runefang Steel with Silver, when Silver is much, much brighter, and there are closer metallics in the VMC range.
My best advice is to go to a hobby shop that carries both paints. The VMC counter will have a swatch where actual paints are painted onto a white cardboard (I find it hilarious how different these colors are from the indicators on the shelf). Then, take a Citadel paint pot, and compare the bottom of the paint pot to the VMC swatch.
Unlike Vallejo, where some of the colors look quite different in the bottle than dry, Citadel colors look almost identical to what's in the pot.
There are a lot of colors in both ranges where there just isn't a match that's all that close, and I wouldn't fight it. Either use the paint from other range, mix the color, or give up and settle for models looking different. Black Grey on your list is a good example -- there is nothing close to it on the
GW range. The darkest colors are Eshin Grey and Skavenblight Dinge (almost identical), which are mich lighter than Black Grey. In fact, for Citadel paint fans, it's a good reason to buy Black Grey