The way Hiruzen handled Naruto and the Uchiha just makes me dislike his character. This guy allowed a CHILD to be hated for something he didn't even do. He didn't try everything in his power to make things right with a discriminated against and feared (within their own village) clan that served them time and time again in wars. He even allowed a rogue student of his roam free and terrorize countless clans, small villages, and wayward individuals. Not only that, but I'm pretty sure the 3rd ninja war started with him still as Hokage and the 4th took over soon after. He was easily manipulated, despite having such a keen mind.
Tsunade really helped Naruto and pushed him to greatness when only Jiraiya really gave him a chance. She really pushed for better relations between other nations. Her prowess in healing saved a lot of villagers during attacks. Her teachings to Sakura, a failure of a character (not bashing) pushed her to be a valuable teammate and eventual asset to the whole village. She didn't discriminate at all and didn't get manipulated by total BS. She wanted to help Naruto save Sasuke (or at least allowed it).. which was also giving a chance to an Uchiha.
In my book, Tsunade set the village on the path that lead to it's current development. This alone makes her superior to Hiruzen along with her other listed feats above. She was better. Hiruzen was best at strategy and an army general type position. That's the only reason why he was picked at a time of still fairly constant war.. and didn't change even after things settled a bit.