If we are to learn from Mahabharata, Drona as a Brahmin was barred from participating in active warfare until Kurukshetra presents him a theatre. But nonetheless his heart remained in the study of the art of war. He studied the science of war intellectually, developed regimes to conditions him self physically and with a single minded devotion to what Parashurama bestowed him with- Knowledge.
He understood whatever is possible first hand. Perhaps this is one reason why Drona felt immense compassion for Ekalavya had not his sense of duty and a whim of a spoiled and insecure royal (Arjuna) blocked his natural instincts. He was the object of ridicule of every Kshatriya except the discerning eyes of Bhishma who let him be the Acharya of the Kura and Pandava clan. Would you say that Drona did not have the experience of war and was not eligible? May be, but had he not the experience he could not have pulled out the clinical carnage of the Pandava army. A spectacle that will make the bowels of a Kshtriya squirm. Krishna had to rely on treachery to enable Drona’s slaying. His experience came about because he abides by the knowledge and the practice of the science of warfare. The experience is in that knowledge and its practice is beyond and immune to the conjectures of the common sense.
Never assume what shape your experience will take, let it unfold and it will leave you with knowledge worth a many lifetime.
Sattva Mushti Taijiquan 