The problem with cereal grains their nutrition levels are very low. If you look at this study The importance of promoting a whole grain foo... [J Am Coll Nutr. 2002] - PubMed - NCBI The Importance of Promoting a Whole Grain Foods Message presented as part of the grains for health symposium or some such
"Whole grains deliver a unique nutrient package. Rich in phytonutrients, whole grains contain vitamins and minerals, unsaturated fatty acids, tocotrienols, tocopherols, insoluble fiber, phytosterols, stanols, sphingolipids, phytates, lignans, and antioxidants like phenolic acids  (Fig. 1). The average antioxidant activity in whole grain cereals and whole grain breads is at a level similar to that of fruits and vegetables, on a per serving (Table 1) or a 100 gm basis."
They want to compare 100g serving of eat the problem is on a per calorie basis they fail.
100g of bulgar wheat = 360 cal
100g of tomato = 18 cal
100g of broccoli = 35 calories
Looking at those sorts of number veg is 10-20 more nutritious than grains....and we have not started with animal protein yet.
They may have a complete complement (ish) but you could never eat enough.
In addition 100 g of sugar has 387 cal ...only 27 more than bulgar wheat.
Eating primal is not a diet, it is a way of life.
Don't forget to play!