I'd take ratings from sites like this with a very large dose of ... well, not exactly skepticism, but certainly, caution. Remember: anyone can put up a website. I have problems with sites that are run anonymously without revealing who is doing the reviews, what their qualifications for reviewing are.
Beware what you read about foods; an awful lot of it sounds like it must be based on nutritional fact but actually is pretty questionable. And a lot of it simply has no meaning for most dogs. For example, while it is useful to caution that wheat and corn can cause allergies in dogs, it causes them in tiny minute fractions of dogs. And the argument that dogs don;t eat grains in nature -- well, actually, they clearly will eat grasses and so forth and value the roughage... and get semi-digested grains regularly from eating the stomach of small rodents or grass eaters wild canids would feed on... they also don't dig up and eat carrots but a lot of us offer fruit and veg as healthy low cal treats and for roughage etc (and coyotes for example are known to scavenge berries, windfall fruits, etc). And keep in mind that in the wild, canids eat primarily sickly, dead and decayed protein sources -- not nice fresh human grade sources. Even top canid predators such as wolves do not hunt and kill healthy animals. They cull the sick, the elderly, the weak, the dying. They scavange dead and rotting animals. So feeding a raw diet based on nice human grade meats in pretty little medallions to echo the menu at your local bistro is pretty far from what any canid on the wild would ever go near. Definitely good healthy food choices for your dog, but it is not anywhere near the 'best replica of what dogs would eat in nature".
All that is why I say to not get overly worried about what you feed a dog as long as the quality is good. Supermarket-available foods are all pretty low quality ultra cheap foods with lots of fillers and preservatives. Find a good quality dry or tinned food or homecook or raw feed something that suits your own preferences and your lifestyle Personally I think variety and freshness and quality should top the list of desireables and those can be satisfied in many different ways.
As a guideline for foods, I recommend the Whole Dog Journal's list (where Royal Canin's natural blend is regularly one of their top 30 foods and they pretty much rank the rest of the RC foods, with similar if not organic ingredients, to also be a good choice).
5.22 kg I forget how to convert, I always have to ask my hubby.