This may be a little shallow, but another reason why Dorje Shugden is a Buddha and considered such a High Being is because when an oracle takes trance of Dorje Shugden, all High Lamas makes offerings of Body, Speech and Mind to Dorje Shugden.
But when Kache Marpo takes trance, it is He who makes offerings of Body, Speech and Mind to the High Lamas.
Am I right to say so?
There are many videos on youtube where we can witness this.
Actually, it should be noted that the Protectors in trance always pay respects and make offerings / pay homage to the Lamas, and not the other way around. The protectors listen and support what the Lamas say, and not actually the other way around. You will notice that if a Lama has already given a certain instruction or teaching to his students, the protector will never contradict or go against what the Lama has said. You will find that the protector's proclamations, advice and guidance will always perfectly match exactly what the Lama has already been teaching to his students.
When the Lamas (or his assistants) make offerings to the protector in trance, it is not that the Protector is "higher" than the Lama; it is that the Lama or his assistants or representatives make extensive offerings (or serkym or Tsok) to collect a large amount of merit on behalf of the students, his Dharma organisation or the many beings that will be benefited in the future by his works. The collection of this merit is very important so that the answers can come through clearly for the students and that they in turn can listen to and receive the answers clear and practice.
So you might wonder - if the lama is higher than the protector, then why do we even seek the counsel and advice of the protectors in trance? This is a very significant point to note. Yes, actually, we should follow the advice of our Lamas directly, as they teach and advise us. Often, the Lamas will agree to or instruct the protector to take trance through an oracle not because he does not know what to advise his own students or what decisions to make, but because many of the students will not have faith in or believe the Lama. For many students, they will still require hearing the answers directly from a deity for them to believe, develop faith and practice. In actual fact, it is the other way around - it is the Lama who makes the perfect decisions and gives the perfect advice for us. The Protectors support what he has advised and taught, clearing the way and creating the conducive conditions for him to manifest his works, visions, goals and intentions for his students, and all sentient beings.