Our army protected by Bhishma is unlimited (more then sufficient) their army protected by Bhima is limited, (may be sufficient).
अपर्याप्तं तदस्माकं बलं भीष्माभिरक्षितम्। पर्याप्तं त्विदमेतेषां बलं भीमाभिरक्षितम्॥