Zhang Chi had figured that Long Yi's visit was unlikely to bear ill will, probably just appearing as a high-bearded figure mingling with the crowd. As long as he didn't offend him, nothing major would come of it.
Zhang Chi would then do the opposite, pretending not to know the visitor's strength.
This was the normal reaction. The other party hid their aura. Without Gu Youyou, Zhang Chi wouldn't have even noticed him, and even if he did notice, he wouldn't know the stranger's identity and strength.
As such, if Zhang Chi showed he knew who the other party was from the start and acted excessively respectful, then he would be in deep trouble.
On the contrary, treating the other party as an ordinary invader, courageously brandishing his sword, and engaging in a friendly competition, this was the normal response of a genius.
It was the same logic when guessing that Long Yi was Long Yan's brother.
It didn't matter if he was wrong.