The forces of the Pandavas are limited, being protected by a less experienced general, Bhima, who is like a fig in the presence of Bhisma
Bhagavad-gita As It Is
BG Chapters 1 - 6
Our strength is immeasurable, and we are perfectly protected by Grandfather Bhīṣma, whereas the strength of the Pāṇḍavas, carefully protected by Bhīma, is limited.
Herein an estimation of comparative strength is made by Duryodhana. He thinks that the strength of his armed forces is immeasurable, being specifically protected by the most experienced general, Grandfather Bhīṣma. On the other hand, the forces of the Pāṇḍavas are limited, being protected by a less experienced general, Bhīma, who is like a fig in the presence of Bhīṣma. Duryodhana was always envious of Bhīma because he knew perfectly well that if he should die at all, he would only be killed by Bhīma. But at the same time, he was confident of his victory on account of the presence of Bhīṣma, who was a far superior general. His conclusion that he would come out of the battle victorious was well ascertained.