Although Nelson is famous for defeating Napoleon's fleet in the 1800s, we must note that Napoleon's strength was land: at sea he was like a novice. Any competent general could have defeated Napoleon's rotten fleet.
On the comparison, Yi not only had the less strategic advantages and less supplies, he also won the most spectacular battles: in one sea battle, he crushed the 300 Japanese ships with 13 of his own, none of which were his famous Turtle Ships! He also never had formal military training, nor any defeats at the sea: he was the natural genius!
Such was Yi's success that even the Japanese- Korea and Japan have been enemies for hundreds, if not thousands of years- admire him.