Dronacarya's was a very great power in the military art (Chapter 1 Text 4)
Chapter 1: Observing the Armies on the Battlefield of Kuruksetra Friends,
atra sura mahesvasa
yuyudhano viratas ca
drupadas ca maha-rathah
atra--here; surah--heroes; maha-isu-asah--mighty bowmen; bhima-arjuna--Bhima and Arjuna; samah--equal; yudhi--in the fight;
yuyudhanah--Yuyudhana; viratah--Virata; ca--also; drupadah--Drupada; ca--also; maha-rathah--great fighter.
Here in this army there are many heroic bowmen equal in fighting to Bhima and Arjuna; there are also great fighters like
Yuyudhana, Virata and Drupada.
Even though Dhrstadyumna was not a very important obstacle in the face of Dronacarya's very great power in the military art,
there were many others who were the cause of fear. They are mentioned by Duryodhana as great stumbling blocks on the path
of victory because each and every one of them was as formidable as Bhima and Arjuna. He knew the strength of Bhima and Arjuna,
and thus he compared the others with them.
Source: As It Is by HDG. A.C. BhaktiVedanta Swami Srila Prabhupada