As such it is understood in the beginning that one who does not follow the foot prints of Arjuna, cannot enter into the mystery of the Bhagavad-gita and therefore nobody can preach the gospel of Geeta without knowing its mystery.
There are thousands and one scholars in India and abroad but very few of them have followed the foot prints of Arjuna except the Vaisnava Acaryas such Sri Ramanuja, Sri Madhya, Lord Caitanya, Sridhara Swami, Madhusudana Sarasvati, Vishvanatha Cakravarti, Baladeva Vidyabhusana, etc. and many others who have followed the bona fide Acaryas.