I was always under the impression that Ned was more of a battlefield brawler (though not literally) who thrived more in the chaos of battle, whereas Jaime was more of a one-on-one, precision+power+finesse type fighter. I mean, what battles did he fight in? The Whispering Wood, Robb and his men capture him, essentially. Didn't he also lose some fights back in the day of Arthur Dayne as well?