Zhou Zheng didn't come to the Apocalypse Rogue just for armor.
After securing the armor, Zhou Zheng turned his attention to weapons.
Whether it's a single dagger or dual daggers, a rogue can handle them both. In group battles, the power of dual daggers is unmatched. Through several real battles, Zhou Zheng realized that a single dagger wasn't convenient, so choosing a dagger became necessary.
High-rate weapons were out of the question for Zhou Zheng; they were unnecessary.