Ah yes, let the Outcasts siege Newark to make it an Outcast base.
RP/10
In the majority of cases, it wouldn't make any sort of RP sense for an unlawful organization to assault any but the farthest outlying stations due to the lawful forces being able to deploy crushing reinforcements. You must keep in mind that while the Outcasts have a sizeable presence in the far north Omicrons and the Taus, their physical presence in the Houses is negligible, save for the borders of maybe Gallia, Kusari and Bretonia.
The Rogues from an RP standpoint have the facilities to field one or two destroyers, that's it. The Xenos can't even maintain their snubs, let alone capital ships. Their total population is under 15,000.
In Kusari, the Dragons have one or two scrapheaps known as Togos in service, not nearly enough to threaten really anything in Kusari for any period of time. The GC might be able to disrupt supply lines to a station for a couple of days by using clouds for cover, but ultimately, they'd get roflstomped by KNF.
In Bretonia, well, they do have the single weakest military out of all of the houses at the moment, but even so, it would take a coordinated effort from the Corsairs and other local criminals to be any threat inside of House space. They might be able to take Sprague, but that's it.
In Rheinland, you have an interesting clusterf*ck. Hessians and Coalition on one side, Corsairs on another and then the Unioners over there doing their own thing. Hessians, with a sizeable navy of their own could probably take over Kruger's operations in Omega-7 and Daumann's in Omega-11. Would they be able to hold them, not a chance.
Nobody cares about Gallia and I know absolutely piss all about it so I'm not going to dive into that.
So, in closing, your system doesn't make any sense from an RP and lore perspective and poses no real benefit to anyone other than established players who have no lives. We've done a siege event in the past, it was mediocre at best. There was a ton of drama from all sides and ended up with Shooter going to the people on the Outcast side saying something to the effect of 'make it quick'. One side overpowers the other and it becomes unfun for everyone.