There is some controversy around this, but the basic is that Surya Namaskar is an exercise which is a mix of 12 postures and these postures are not newly invented they are from the basic Yoga practices but just brought together as one sequence as it has been observed that these set of Asanas would work perectly for overall mind & body health. Likewise there are a lot of other sequences also which do not root from the ancient yoga scriptures but over a period of time it has been noticed that when certain Asanas and breathing practices brought together will give very good results, like the Yogaasana, which has been introduced by Sadhguru. The whole point is when something works best you should embrace :-) That's what Yoga helps you with - Realize the supreme spirit that you are