Well it does suck Zack dies in such a cheesy way, you'd figure as badass as he is, plus after whatever Hojo did to him after the Nibelheilm Incident he'd be way more kickass...but no, they still shoot him down, so, to me he's labled as a failure, where Cloud, mako-poisoned and completely stupid at this moment is left to live, steals Zack sword, crawls to midgar and survives until the end. I would say Cloud > Zack on that alone.