Duryodhana continues naming Pandava allies. Dhrishtaketu was the king of Chedi, Chekitana a celebrated Yadava warrior, and the king of Kashi was known for his valor. All of them stood with the Pandavas.
Purujit and Kuntibhoja belonged to Kunti's own family. They were the Pandavas' maternal relatives, warriors from their mother's side. Shaibya was the distinguished king of the Shibi kingdom. By mentioning all of them, Duryodhana makes it clear that the Pandavas have gathered support from every direction.
When someone keeps counting his opponent's allies, it tells you where his mind is. The longer Duryodhana's list grows, the more his underlying anxiety shows through.