Numbers alone will not tell you which is origin of another. DNA will.
Ezidi has been through 73 previous massacres committed against Ezidis in the last 1400 years.
My Syrian Kurd friends tell me that all Kurds descend from Ezidi.
I do know they have over time adopted some elements of other religions.
It is confused with Zoroastrianism by outsiders.
They frown on intermarriage outside the group.
Thanks. And, as with the Jews, over time “original groups”, particularly with a history of frequent pogroms against them, often adopt endogamy - the social restriction against marrying outside the group. So, it does make sense, what you say, about the Ezidi being the “root” and “the Kurds” the branch - even though the Kurds are now many more in number.
What has always intrigued me about the Kurds and the Ezidi is when we take the history back to as far as ancient people knew them as distinct group(s), they (a) are not much further removed in time from Abraham as are those we later identify as Jews, and (b) they occupied areas of Mesopotamia not distant from the area from which Abraham began the trek (from Hurran in what we now call Iraq) that eventually led his descendants to Israel. And here we are today with that area still the center of so much that is challenging the world.