This is where cat foods usually don't measure up, as they often contain too little protein compared to fat. Food in tins usually contains more water than dry food, so the percentages cannot be as high. And since you don't know exactly which types of proteins and fats they contain, this can only be considered as general guidelines, and you'll have to see which food works best for you. You cannot live of only protein, fat and carbohydrates. For example a small amount of fibres is good for digestion.
Vitamins are a difficult subject, as the sources differ very much in their recommendations.
You cannot live on stored water soluble vitamins, for example B, as they disappear from the body every day, so you don't have to worry as much about over dosing them. The conclusion I draw from all this, is that cat food is OK for the most part, but I don't consider it sufficient for at ferret, at least not year round, as it often contains too little protein compared to fat. Which of them is best I cannot say, but they contain different things and smell differently. Marshall's smell most like cat food, and as only two of my four wants to eat Ferret Complete, that's the one I use now. Plus any remaining cat food.