Interesting idea.

However the MHCM was a super AI working in conjunction with the military leaders of Nabushan (i've assumed).
That means faking top security pre-war signal relays, to send out fake orders.
Needless to say this is very complex.

A more sensible way to try and fake it would be to get a bunch of guys into pre-war Nabushan uniforms, then pretend to be pre-war infantry.
This way one doesn't have to get control of the matrix network, however that also means that the troops wouldn't actually have any control over KR 112. But can make requests there is a decent chance MK IV would grant.

I'd say it's probably easier to just try and make contact with the KR 112. (Provided one knows what it is, and is not afraid of it.) Then just begin negotiating with it.
MK IV is gonna be more human than some of the human characters in this RP, so it will probably work well to just speak with it.

However the KR 112 is probably just myth to many factions, but i'm open to some sort of past as i've done with the Cybrans.
Whom have some cultists as permanent 'interior decoration' on the KR 112. But that was because of a misunderstanding.