This represents a total misunderstanding of what Dzogchen is and what Vajrayāna is. Dzogchen is not separate from Vajrayāna in anyway shape of form. Dzogchen is a part of Vajrayāna Secret Mantra as even a cursory examination of the basic texts of the tradition will indicate.Vajrayana is just catching up with Dzogchen being removed from preliminaries and other rituals to turn into another form of mindfulness practice.
Further, Dzogchen may not necessarily involve the four hundred thousands famous to us, in fact one of the earliest presentations of that sequence of practice is to be found in the klong gsal nyi ma 'bar ma tantra, which forms the foundation for most of the Nyinthig cycles from the Khandro Nyinthig onward. Moreover, there are a series of preliminary practices in Dzogchen that are indispensable such as the separation of samsara and nirvana, semzins, and so on.
Empowerment is absolutely necessary in Vajrayāna. Dzogchen Atiyoga is merely one of three inner tantra divisions. It is not in any way separate from Vajrayāna at all. Not only, they are hardly "another form of mindfulness practice."
Stick to Zen, Astus, you are out of your depth when commenting on Tibetan Buddhism.