Indeed the conquest of the americas didn't include that many battles anyway. The enormous success of the conquest was mainly based on the European diseases that the American population were not resistant to, causing them to be decimated in a few years.
Unless you count Pizarro's conquest of Cajamarca, when 37 horse bested 80,000 (I kid you not, eighty thousand!) foot. (described in Jared Diamond's classic book Guns, Germs and Steel http://www.pbs.org/gunsgermssteel/show/episode2.html).
Now that would be a weird and somewhat disappointing Total War battle, and everyone would scream at the AI...