[quote=@Jbcool]
Just so I'm clear o everything;

We're all gonna burst out of a civilian 'munitions transport' into the midst of the Governor's fortress, and massacre everyone?

That about right?
[/quote]

That's about right. Well, overwhelm his paltry only-human guards, who probably would like to be able to tell their grandkids that they survived an astartes assault. And then they're in the corridors, where numbers count for less...

Edit: Except it's not a munitions transport. It might be carrying food, teddy bears or dildos according to the manifest. Perhaps all three.