In the process of lauding Gen. Ulysses S. Grant, President Trump praised Confederate General Robert E. Lee, saying Lincoln needed a Grant to beat him. Many have criticized this praise, and claimed it is racist.
Nonsense. A general who can win battles - many actually - with inferior forces is a very good general indeed, regardless of which side he works for. Robert E. Lee was demonstrably a good general, as was Hitler's Erwin Rommel, aka "the Desert Fox." Neither worked for a side that ultimately won, which doesn't matter, they were skilled tacticians.
The fact a skilled general works for the other side is something you can realistically be sorry about, can regret, but it takes nothing from his ability to direct battles. To use a sports analogy, you can admire the skill of a quarterback, or running back, even if he plays for the opponent's team.