It’s an impossible question to answer. There are some truly fantastic generals that we know about, and all had some chance at defeating any of the others under the right conditions. Flat out, Napoleon had the most recorded victories of any known General, and in his prime he was certainly a contender for top spot, but he never had to fight the Golden Horde, possibly the only pre-modern army faster than him. He had Marshalls under him that would also qualify as top of the line generals in their own right. Archduke Charles, one of the only men to defeat Napoleon while Napoleon was at in his prime, would also have to be on the list. Then there is the great Korean general Eulji Mundeok, a man capable of directing hundreds of thousands of men while fighting terrible odds and coming out on top, or Emperor Tokugawa, who had one of the most elite medieval armies in the word, or any one of a dozen ancient and classical era Chinese generals…