Ye Weiming did not keep the Unparalleled Sword with better attributes for his own use; instead, he presented it along with the other Unparalleled Sword to Ming Qiao, clearly with his own considerations.
In fact, although the attributes of the Unparalleled Sword may seem intimidating, compared to his own "Sword among Swords," it was only a bit stronger, and the gap wasn't truly significant.
But compared to Ming Qiao's original pair of Artifact Sharp Swords, the difference was huge.
Considering that what lay ahead were surely fierce battles, it was of course necessary to enhance the team's overall combat strength as much as possible!
Ming Qiao's initial intention was to reject the Twin Unparalleled Swords when she saw Ye Weiming bringing them to her.