In principle.
The Mechanist Cult and the Empire existed in a state of cooperation. They did not worship the Emperor, nor were they subject to the Imperial Regency Council, possessing their own autonomous systems for taxation and military development.
In other words.
The fact that they could sit as equals with the behemoth that was the Human Empire, even holding the upper hand in negotiations, was because the instruments of violence and high-end military power under Mechanist Cult rule were, compared to the Empire's, equal, if not superior!
The Defender Army, whose scale was no less than that of the Imperial Infantry Corps.
The Titan Legion.
The Mechanical God Guard.
Far more than any de jure standing or traditional alliance, these three military forces were the true reason the Mechanist Cult could stand as a rival to the Human Empire.
