If you look into what are called traditions you find that they are combinations and systematisations of other traditions of teachings and practices. And within a single tradition there are smaller and greater differences among individual teachers. So, if we go on with our analysis of the concept of tradition, we find that it is indeed not a single thing but a manifold, constructed and dependently arisen phenomenon. Practitioners have always tried to benefit from whatever they had at hand and as teachers they transmitted those that were the most helpful on their path. It is only natural that since in English we have teachings from several sources we make use of them.
"While teachers of the middle way, mind only, transcendent wisdom, mantra, and other schools may have their own assertions, the fulfillment of those intentions is the same. There is not a single thing that is not contained within mind."
(Gampopa to Düsum Khyenpa, in "The First Karmapa", KTD Pub, p254)
“If you recognize the world of appearance and existence as the mind, realize the mind itself as empty, and have no grasping at the superiority of your realizations — this is the ultimate view."
(Chegom Dzongpa, in "The Book of Kadam", Wisdom Pub, p609)