Imperfection exists in all and everything including different yoga schools or yoga teacher training courses and the people involving in running the yoga schools and yoga courses.
With an open mind, without expectation, be ready to inquire the truth of everything, including all the teachings and practice presented by the yoga school or in the yoga teacher training course, and without regret towards one’s decision of choosing the particular yoga school or yoga teacher training course.
Dealing with all the pros and cons or imperfections existing in the yoga school or the yoga teacher training course with an open mind, and be able to make decision without regret, is indeed the practice.
Follow one’s conscience towards finding which lineage of yoga that one would like to explore and experience. It’s okay if one finds that after experiencing a particular lineage of yoga, one realizes it doesn’t suit oneself. If so, be open to experience some other kind of lineage of yoga, until one finds the most suitable one. In the end, it’s not about which lineage of yoga or yoga school that is the best among all, but it’s whether the mind is being unattached towards and unidentified with the particular lineage of yoga, the yoga school, the teachers, the yoga teacher training course, and all the desirable/undesirable or agreeable/disagreeable experiences.
Above all, it’s not about getting the best ‘Internationally recognized yoga teacher certification affiliated with such and such yoga alliance/organization’ from the best yoga school and yoga teacher, but it’s about being open-minded upon coming in contact with the different kinds of teachings and practice from the different lineage of yoga, to be purifying and quieting the mind, inquire towards the truth of all the teachings, and the truth of ‘I’ or ‘who am I/what is the ego’, realizing selflessness/egolessness, be free from ignorance, egoism, impurities, restlessness and suffering.
Attending many yoga teacher training courses in certain yoga schools and attaining many yoga teacher certifications and teaching many hours of yoga classes doesn’t determine whether the mind is free from ignorance, egoism, impurities, restlessness and suffering, or not.
In the end, one will realize the greatest teacher and the greatest ‘yoga course’ is the mind itself upon being rendered pure and quiet through the different kinds of persevered practice, being unattached towards and undisturbed by all the mind perception of names and forms or the activities/modification of the mind, of all the agreeable/disagreeable, pleasant/unpleasant, desirable/undesirable experiences, and be able to see the truth of things as it is, be free from ignorance and the by-products of ignorance.
Those who are free from ignorance and egoism don’t need to attend yoga teacher training course or attain ‘Internationally recognized yoga teacher certification’ to be peaceful and compassionate, or to disseminate the knowledge of yoga to those who are in need of the teachings and practice to be free from ignorance and egoism.
The ‘real’ Guru/teacher is the one without a ‘certificate’/’recognition’, without a ‘school’/’ashram’ and without giving ‘certification’/’recognition’ to anyone.