Hiruzen gets to take on another Hokage, but he won’t fare any better than he did against Minato. Tsunade is easily one of the greatest Kage that the world has ever seen. She’s excellent at healing jutsu and her monstrous strength allows her to overpower just about any other fighter. Hiruzen doesn’t have her stamina and one good punch would likely take him out of the fight, whether Hiruzen is in his prime or not. Tsunade wins.