Pray do tell in what manner these two fail the test of greatness. You've made me curious. Most especially regarding the Iron Duke, whom I know more of than Scipio.
Also, I'm curious about your claim that Great Britain was a greater nation than France at the time of Napoleon.
This is a timeless question. What is the difference between the great and the merely excellent? How often does greatness go unnoticed, because it fails under the weight of the imbalance of men and material? How do you remove the general from his army, so as to examine him in issolation?
Certainly Scipio demonstrated some of the things that made Hannibal a great general: disciplined forces, knowledge and use of terrain, a knowledge of when to attack and when to refrain. On the other hand, his supply situation was enormously simpler than Hannibal's. His army had the advantage of homogeniaity, formal training grounds, tradition and the backing of the Roman state.
However, this is not sufficient, because it was also true at Cannae. Scipio was clearly better than Pallus and Verro. His handling of the elephant cavalry was certainly ingenious. The discipline and foresight needed was substantial. But SCipio had the best that Rome could offer. Hannibal had a thrown together army of inexperienced troops, a far cry from the veterans of Cannae. In the end it was close, and afterward, the war was over. Scipio had only a short campaign, with exceptional troops, and engaged only one major battle. This is not sufficient to proclaim Scipio as a great general. As I said, a very good one.
Wellington has perhaps the better argument. While he is remembered primarily for Waterloo, the Spanish campaign is no small fete. Suffice to say, again, that Wellington was a very good, perhaps exceptional general, but his accomplishments were much more in line with his means than Napoleon.
Far be it from me to argue that a general is less because he has an advantage. Especially against an opponent that has proven the ability to make ham out of tripe. Grant is unfairly denegrated for not being as audacious as Lee. Similarly Zhukov. One fights with what one has.
J