[Berosus]

I hate to break the news to you, but in its heyday Zoroastrianism was a militant religion, too, especially under the Sassanian or Neo-Persian Empire (226-651 A.D.). The reason why there are so few Zoroastrians today is because Islam proved it was even more aggressive.

A Sassanian knight, or clibanarius, with a standard bearer.

[SunkenCiv]

Quite agree. Zoroaster is the (perhaps fictional or fictionalized) reformer of Zervanism, and the persecution went on both ways.Regarding their ancient scriptures, Mary Settegast wrote:

Plato Prehistorian
by Mary Settegast
[pp 212-214]

Perhaps three-fourths of the original Zend-Avesta... is believed to be lost... The Avesta was not written down until the Sassanian period (the third to seventh centuries A.D.)... Zarathustra's Gathas are particularly obscure... Not only do the Gathas appear to be a good deal older linguistically than even the oldest parts of the Younger Avesta, but the same characters who speak and act with immediacy... are represented in the Younger Avesta as belonging to a remote past... The Fravardin Yast [of the Younger Avesta] ...contains references to Iranian peoples who were apparently unknown to the earliest Achaemenid records of the sixth century B.C. And with the single exception of "Ragha," believed to be ancient Rayy near Tehran, no allusion is made to a known Iranian city or village... A generic use of the prophet's name might also explain the occasional indications in ancient literature that there was more than one historical Zarathustra. Pliny, for example, when referring to the Zarathustra born 6,000 years before Plato, remarked that "it is not so clear whether there was only one man of this name, or another one later on."