The sweet & sour flavor of French, Catalina, and Russian dressings, are a good counterpoint to the seasoned beef, greens, Sharp Cheddar cheese, crushed tortilla chips, and lettuce flavors in Taco salad. I like to combine chili powder and a bit of Sriracha to Russian dressing. The flavors just work.
For an tossed salad, comprised of lettuce, and veggies, I love berry vinaigrettes. But if I'm eating a taco, there has to be guacamole in there.
Americans tend to love sweet and sour salad dressings, especially with the youth. It's oly been the last twenty years or so that we've been introduced to such a variety of differing food styles, in most of rural America.
Seeeeeeya; Chief Longwind of the North