There’s actually two issues going on here. First of all, you’re concerned that you have an incomplete protein and how to count that. There are two answers to that- as everyone else pointed out, if you’re eating a balanced diet, the proteins will combine and complete themselves in the digestion process. The second answer is that there are specific foods that compliment each other and form complete proteins. If you eat legumes with nuts, grains, or seeds throughout the day, you have yourself a complete protein.
For instance, almonds with lentils, or the famous rice with beans. It doesn’t matter whether or not you eat them together in one sitting, if you eat both of the foods at seperate times throughout the day, they’ll find each other and form a complete protein.
However, if you’re trying to get big, that isn’t your main concern. Your main concern is actually the biological availability of the protein. For instance, if you eat 10 grams of soy protein, your body will probably absorb/utilize around 4 grams. The rest is expelled. With whey or eggs, it will absorb over 7 grams of that 10 grams. When you eat incomplete protein sources, this number is closer to that of soy than with whey (obviously). So yes, you will get a complete protein, but it’s not an equal protein. There are many different ways you could use that knowledge. If it were me, I’d count the protein grams, but also make sure that I’m going over my daily allottment when I do.