My point is rice is less than ideal food and while better than nothing the Op need decent protein sources.
Let's aim right at the heart of your argument.
You require carbs, fats, proteins, fiber, vitamins, and minerals to have a balanced diet. You don't get to cherry pick that list either. You need all of them.
Switching from rice to beans is wrong because you need the carbs from starch for energy that beans don't typically have. But I didn't say you should not have beans either. You should have BOTH!
Did you read your own link? Your cup of black beans has only 14% of your necessary carb load for the day and only 11% of your necessary calorie load.
So you would need
9 cups of cooked black beans per day to get a proper energy load. That leaves you with little room to get the rest of your nutrient base, not to mention an insane amount of black beans to store.
I suppose you could boost that with a lot of fat, but I assure you that fat will likely be the hardest thing to obtain post SHTF. And switching protein for your primary energy load will be a heavy strain on your kidneys. That is just a medical fact there. High protein low carb diets are very hard on your renal system.
You want to make this an either/or comparison. You can't. Nutritionally and economically you need both products. Nothing wrong with your black beans and there is nothing wrong with the parboiled rice either.
If you try to focus all your primary storage efforts mainly into one food type you will fail nutritionally.
[edit] That website you reference is not perfect. Discrepancies have been found over time and thus why they have a disclaimer.
Nutrition Data's Opinion, Completeness Score™, Fullness Factor™, Rating, Estimated Glycemic Load (eGL), and Better Choices Substitutions™ are editorial opinions of NutritionData.com, given without warranty, and are not intended to replace the advice of a nutritionist or health-care professional. Nutrition Data's opinions and ratings are based on weighted averages of the nutrient densities of those nutrients for which the FDA has established Daily Values, and do not consider other nutrients that may be important to your health or take into account your individual needs. Consequently, Nutrition Data's higher-rated foods may not necessarily be healthier for you than lower-rated ones. All foods, regardless of their rating, have the potential to play an important role in your diet.
Just for the record, I don't come with a disclaimer. As an IV certified pharm tech I am a nutrition certified specialist.