To the other end of the question, I find that added sugar gives an undesireable flavor component to tomato sauces. Many recipes have a set quantity added to a given volume of tomato product, which is often one with variation in acidity and sweetness from batch to batch. Ergo, you get sauce that can at times be unbalanced acidic, and some unbalanced sweet/candylike.
My philosophy is to buy one of the top tier fresh-pack tomato products and work your recipe from there. They are very sweet and balanced tomatoes that seldom, if ever, require adding corn or cane sugar to the recipe. I am a fan of Stanislaus, and other here use Escalon. Still others use other high consistency manufacturers. Get fresh-packed tomato samples and see what you get without the sugar. I pay about 4 cents over USFoods house lable per 16-inch pie to use Stanislaus. The sauce results are worth far more than 5 cents to me. I will be that the people using top tier tomatoes are not cooking sauces before making the pies. They are looking for the fresh tomato character you get from those brands. IT may actually help some of the truly “sad” brands of tomato to cook and develop more complex compounds so they taste better. Just sayin’.
I use a very simple seasoning: to 5 cans of tomato, I use 4 ounces of seasoning . . . . oregano, granulated roasted garlic, black pepper, and basil. That’s it . . . TOTAL of 4 ounces . . . so that I feature the tomato, and let the spicing be enhancement to that tomato. Just my way of seeing the pizza world; let the tomato be tomato.