Sanatana Dharma is based on the Eternal law that the soul is one, but the shades of the mind and Maya are infinite. So, practices in one system may not fit the bill for different types of Jivas, who come from different conditioning, with a different history of their journey from their previous life times. The Dharma has evolved extensively to address each type of Jiva. Hence there is a variety in the approaches towards that one single Truth.