I don’t think it’s accurate to call Lexington style tomato based. I have found most Lexington sauces to be nothing more than an eastern style with a little ketchup added. The point is the two have a lot more in common than people make out to be. But, of course if they didn’t we wouldn’t have anything to argue about. I was always told that the two Bridges were not related but who knows? They both make very good bbq.
which is exactly what makes it tomato-based (compared to eastern style) and clearly distinct from non-tomato-based Eastern style. It's referred to being tomato-based to distinguish it from the original, not because tomato tends to dominate that much.