Umm, this is an interesting/debatable topic, but the objective is undeniable. If two people believe in two COMPLETELY different things, and that there is only one definitive answer, then obviously someone has to be wrong, there's no way around that.
If Shaheed Bhai Mani Singh Ji and Shaheed Baba Deep Singh Ji BOTH read Raagmala then I don't understand why this topic needs to be discussed, because who could know Kalgidhar Patshah better than his 'best friend' (Bhai Mani Singh Ji grew up with Guru Gobind Singh Ji Maharaj) and Shaheed Baba Deep Singh Ji (read his jeevan, its amazing how much he did for the Panth.)
In regards to the question, if you know anything about Baba Nand Singh Ji Maharaj, Baba Isher Singh Ji Maharaj (Nanaksar), Baba Attar Singh Ji Maharaj you'll see how they had EXACTLY the same opinions/practices as each other. So, personally, I believe them to be PURAN Bramgyian's beyond a shadow of a doubt.
Finally, the most important thing to take away from the video is that, no matter the "Dera" (be it Nanaksar, AKJ, Thaksal, 3HO, Rara Sahib, Baru Sahib etc.) they all had three common objectives...
1) Khande Bateh Da Amrit (Give your head to Guru Nanak Dev Ji Maharaj).
2) No meat, alcohol, intoxicants.
3) And most importantly, GURU MAINO GRANTH... nothing BESIDES the Guru Granth Sahib Ji Maharaj is our Guru.
Oh well, read any of their Jeevans, and one can only be inspired to learn more and try to achieve something that they'd be proud of.
Bhul Chak Maaf if I've said anything wrong.
Note: Topics that are not Allowed.