Didn't Need An Army

[Errorname]

That's moving the goalpost.

I'm trying to clearly establish the goalposts, this has been my stance the entire time. I may have been unclear, because discussing the specific failure points of a scheme to usurp the city is a lot of fun but it's a separate argument, arranging a coup through a rival lord is still taking the city with an army in my view.

Team Evil would not be in command of the army, nor would the army be used in any phase of the operation. The city would be under civilian control for the entire operation.
No army is used either to take or to maintain control of the gate.

An army is used to maintain control of the gate: The Azurite army. In this scenario you're dealing with them as a threat by subverting them to your will, but still involves bringing the army under your control through your proxies in the nobility.