I wouldn't be switching the kittens diets. This will cause severe diahrea, and they can become dehydrated. Keep them on the dry kitten food, or mix with water. Their digestive tracts are very sensitive at this time. You will just make them sick. Not from the carrotts, but from switching their diet. I have fostered kittens for the last three years, and one little switch, even switching brand of the food will give them diahrea. You do not want them to become dehydrated!!! They can die from this.
Ditto what Wiley said. Cats are carnivores. And kittens, especially, should be fed a good kitten food and stick with it. Don't be switching their diet around. You are making everything a lot more complicated than it should be.