Zoroastrianism evolved over time and various groups split off partially, such as the Mithraists, Zurvanites and even Manichaens.
I think it’s entirely reasonable to place the Yazidis solidly in this group of Zoroastrian-offshoot religions. Heavily influenced of course by Islam and other, possibly even pre-Zoroastrian religious influences. There are obvious parallels to the religion taught by Mani.
My mother and her family are zoroastrians by birth through generations. Still close to zoroastrian community & traditions. I was writing previous comments from personal experience as well.
Mithraism is the only ‘religion’ that came before zoroastrianism. Zurvan & manicheanism both came after. There is no concept of ‘peacock worship’ in Z faith; nor in mithraism. Most Yazidi beliefs (theologically) are quite foreign to zoroastrians.
This link is from 2011 mostly about zoroastrianism.
http://www.freerepublic.com/focus/f-religion/2717607/posts#44
Actually, whilst the peacock is a fairly popular animal in persian history and we often see it in persian paintings particularly post-islam, it originated from india & is an indian influence. Including ‘the Peacock Throne’ which was brought to iran over from india during a muslim dynasty (Nader Shah) in iran. Though am not suggesting it is a hindu religious tradition.