
What you need to do is reduce both to dry matter. Divide the protein by the dry matter eg 26 divided by 92 x 100 =28.26 and 12 divided by 25 x 100 = 48.
Now typically you would feed 200g of dry food, and likely 500g of moist complete (or 300g with equal volume mixer, shich is about 150g). In the first example you would be feeding 52gramnmes of protein, and in the second 60grammes.