Jiang Hao had never intended to get involved. However, he happened to be nearby and couldn't refuse to help a fellow disciple from the same sect.
If only he had seen them beforehand, he would have gone the other way! He had no choice but to put up an act to show his fellow disciple that he was doing his best.
He threw the Ten Thousand Sword Talisman. That was all he was willing to do. The enemy could easily block that attack and leave.
Everyone assumed that he was in the middle stage of the Foundation Establishment Stage, so just trying to help was worthy of praise.
Jiang Hao activated the Ten Thousand Sword Talisman. The enemy had already activated the magic array. His talisman wouldn't hinder the enemy's magic. Jiang Hao wanted him gone more than anybody else.