Do you think both systems are identic?
Of course not identic, but there are as many differences in Yoga-systems as there are in chinese systems.
Despite this there are some extreme practices in Yoga, but in Tempu Nakamura Senseis Yoga system the practices were not of this kind, it's a mixture of raja-yoga and something else.
A Yoga teacher told me in a lessen, that Yoga was about breathing, not about doing crazy things with the body, and about working with energy.
When I do the sun salutation from the ashtanga yoga system, it feels like a practice of heaven-earth-man, its an opening and closing movement emanating from the breathing.
The same feeling I have when I do the breathing exercise Tada Sensei showed us.