Abraham Lincoln lamented for years that the Northern Army of suppression (
) didn't have any generals who would FIGHT and I believe was quoted as responding to a question from an aide about what he wanted and he said "Just give me someone who will fight." Hence, his willingness to promote US Grant, an unabashed alcoholic and the worst tactician in US military history, simply because he DID have the will to step up to the CSA and get down and dirty. So perhaps the will to fight is most important or at least a very necessary ingredient for success.