Tsongkhapa fan, don't take my word for it. Take the word of Lord Tsongkhapa:(Lam Rim Chenmo, Snow Lion edition, pg.50)There are those who conclude that any classic text should be considered only an explanatory teaching, therefore lacking the key points for practice. They hold that there are separate personal instructions that teach the core meanings that are the heart of practice. They then imagine that there are two forms of the excellent teaching- a teaching that is explained to you and a teaching that is practiced. Know that this attitude precludes development of great respect for the stainless sutras and tantras as well as the flawless treatises that comment on their intent....
Therefore, for those who desire liberation, the supreme and authentic instructions are indeed the classic texts.However, due to your limited intelligence and so forth, you may be unable to recognize those supreme texts as the supreme instructions through depending on them alone. Thus, you must seek out personal instructions, thinking "I will seek certain knowledge of those texts based on the personal instructions of an excellent being. But do not think "The texts are without substance, since they merely promote a superficial knowledge and eliminate others' misconceptions; yet the personal instructions, since they reveal the deep meaning, are supreme.
Lama Tzongkhapa is very clear- the emphasis should be on the original sutras, tantras and shastras. In the case of Tantra, this means the root tantras and commentaries of 13 Deity Yamantaka, Guyasamaja and Chakrasamvara, on which Lord Tsongkhapa commented extensively.
The Kadam Emanation scripture- as precious as its teachings are- cannot be held above the great Sutras, Tantras and Shastras. It can be cultivated on the basis of a scrutinizing study of the Great Classic texts. To set emphasis on those texts aside in favour of emphasizing a "Whispered Lineage" does not seem to be in the spirit of what Lama Tsongkhapa is stating here. They are teachings that supplement and enhance what we gain from the great texts of the Indian Pandits and the vast commentaries on those instructions from Lama Tzongkhapa and his two sons.
You seem to be coming around
Originally, you were saying that its possible for Dzokchen to be a Gelug practice since there is precedent such that Vajrayoini, Ganden Chod, Hayagriva are not in Tsongkhapa's Sumbum
Then, when it is suggested that these are really auxiliary practices for Gelug (whose primary practice, Yamantaka, Guyasamaja and Chakrasamvara) you commented that actually HHDL said that Vajryogini was the suggested practice for Westerners with not much time.
Finally, you quote positions that says we should not sweep aside the traditional subjects in factor of Vajrayogini and now we are back to Yamantaka, Guyasamaja and Chakrasamvara.
Hey, I am just being cheeky! Just my way of pointing out that I think everyone agrees here. I think we all agree that the main Gelug positions on sutra and tantra are found in Tsongkhapa's Sumbum. Then there are also auxiliary practices such as Vajrayogini that for some because of circumstance or connection become their main practice. Further, there are some Gelug practitioners that skillfully include practices from other traditions such as Mahamudra and Dzokchen. How wonderful!
There does seem to be a difference in emphasis. While some consider the whispered lineage as heart instructions, others such as HHDL considers them secondary practices. But, I am not aware that anyone really suggests that the whispered lineage should be studied at the expense of the Indian masters.
I found it interesting you posted Tsongkhapa's quote. These comments from Tsongkhapa seem not targeted towards those like the masters of the emanation scripture lineage (who of course came after Tsongkhapa) who from reading their biographies it is clear they were are all great scholars as well as great yogis. They are more a warning against running off to do fancy sounding practices, contained in a few words, without any basic foundation. Something, I think all traditions would agree with!