There cannot be different ācāryas. Ācārya is one. As Kṛṣṇa said in this chapter,
- evaṁ paramparā-prāptam
- imaṁ rājarṣayo viduḥ
- sa kāleneha mahatā
- yogo naṣṭaḥ parantapa
- (BG 4.2)
Ācārya means one who is speaking exactly the same instruction as Kṛṣṇa has given. That is ācārya. Not ācārya, everyone becomes ācārya. "In my opinion it is like..." Who are you? If you have got any opinion, then you write your own book. Why do you touch Bhagavad-gītā? Because Bhagavad-gītā is very well-known book all over the world, these rascals take advantage of Bhagavad-gītā and interpret it in their own way. That is not ācārya. Ācārya means, as Kṛṣṇa says, that "Millions of years ago I spoke this Bhagavad-gītā..." Imaṁ vivasvate yogaṁ proktavān aham avyayam, vivasvān (BG 4.1). "I spoke to the sun-god millions and millions of years ago." Vivasvān manave prāha manur ikṣvākave 'bravīt.