Dhristadyumna

Why was Dhristadyumna made the supreme commander for Pandavas given the availability of Arjuna? Is there a reason they don't want Arjuna to lead the troops? Before war when Yudhisthira asked from his brothers to whom should he choose as chief-commander. Sahadev suggested the name of Virat, Nakul suggested the name of Drupad, Bheem suggested Shikhandi and it was Arjun who proposed the name of Dhristadyumna, which was also approved by Shree Krishna then. Firstly there are some reasons for not making Arjun supreme commander, or even among one of the seven commanders in Pandav army. Starategy of Pandav army was attacking in the whole war, as they were less in number and also in that civil war, they were the challengers. So Arjun being the best warrior of that side, had the responsibility to initiate the attack from the front, break the enemy formation to make way for the army and attack the opponent commander by reaching in the middle of the formation (vyuha). So if he had to manage the army, it would be not effective decision as he had to attack quickly and remain at the front all the time. To manage the army well, the chief commander should be at the middle of the formation. Also the soldiers in the Pandav side were Panchalas, Srinjayas, Kaikeyas, Chedis, Magadhas etc. None of them were formed by Pandav brothers and they did not knew them well. So even if being the most knowledgeable warrior, Arjun played a key role in arrangng the formation (vyuha) and tactics for the battle, but he did not take the charge to manage the execution. Finally if we analyse carefully, we can easily understand why Dhristadyumna got that crucial role. Among the middle aged warriors, leaving Arjun, Bheem and Satyaki; Dhristadyumna was one of the greatest warriors. Also in the Pandav army, Panchals had the major share as they were one of the strongest kingdom then, almost equal to Kuru kingdom. So among the seven commanders, Dhristadyumna was most suitable to be chief commander. Also it was Dronacharya, who always tried to invade through the Pandav army and capture Yudhisthir. As Dhristadyumna was born to kill Dronacharya, he was the perfect counter to him. Dhristadyumna had not the responsibility to break the opponent army to create way for his army as Arjun and Bheem took those responsibility, also he had not direct responsibility to protect Yudhisthir, as Satyaki took that responsibility. So he had freedom to stay in middle to guide the army to continue attacking, following Arjun or Bheem.