Who do you think deserved to unify China?

[Cao Cao]

Though Guts isn't the thing that unifies China
They were just not skilled as the Han Forces were and that seemed to be the Yellow Turbans downfall. (If that is not the reason, please say so, so I can fix my mistake )

[link]

It's difficult to define a force's failing in uniting the land with the word "skill." It's more like a lack of discipline and organization within the ranks of the Yellow Turbans, and their wavering will to fight. After all, the majority of the army was formed of peasants or simple commoners either amazed by the Zhang brothers' healing abilities or ambitious in a thirst to get the empire for themselves. Sure, even Zhang Jiao turned to the latter option as his personal goal, an overthrowing and potential conquest of the land, but I doubt that the untrained, wild men were even interested in that or in fact even realized the true mandate of the war. Which would possibly have led to many deserting upon sight of deep shit or huge massacres due to the fact that untrained troops wouldn't stand much of a chance against official Han army soldiers. That, and the fact that herb and root collectors like Zhang Jiao probably wouldn't have had much of commanding experience or strategy other than their so-called magic.

The novel also implied that Zhuangzi must have cursed whoever used his mystical arts for personal ambition.