As a side note, it may worth remembering that the very idea of Omega Order was introduced in a sourcebook, Corporate Shadowfiles, which also described corporate military as small (the largest being regiment-sized). Hence the difficulty to reconcile Omega Order with the larger military forces suggested in other books, as it wasn't thought that way.

@Cain: Excessive force may carry less risk, but what would be the gain?

I was thinking about Corporate Court mandates at large, not specifically Omega Order against AAA prime megacorporation. Corporations could hardly have an established policy regarding something that has yet to happen.

If a megacorporation with strategic nuclear weapons was to be the target of an Omega Order (and that is a big if), chances are AAA prime megacorporations are not going to take any more chances than AA megacorporations about it. After all, all the corporation who voted the order would likely be considered as legitimate target even if they don't send their own troops in. So, if such situation was to occur, I would expect the order to be voted in secret and operations planned so as to make the first strike decisive. In this case, it's unlikely AA megacorporations would get to learn about it and to participate, whatever their motivation, at least before day two.

As a side note, it may worth remembering that the very idea of Omega Order was introduced in a sourcebook, Corporate Shadowfiles, which also described corporate military as small (the largest being regiment-sized). Hence the difficulty to reconcile Omega Order with the larger military forces suggested in other books, as it wasn't thought that way.

mercenaries. the megas have lots of money and sometimes need soldiers. mercenaries have lots of soldiers and are willing to hire them out to anyone with money.

so if the megas suddenly need a few thousand extra soldiers, they hire mercenaries.

So, if such situation was to occur, I would expect the order to be voted in secret and operations planned so as to make the first strike decisive..

It's a "Court" that all the AAA have reps on. If you bring business before it the members get to hear and vote on it. That's the whole point of it existing.

Aztlan, page 44
All attempts by the Corporate Court to discuss the mater in open session were blocked by Aztechnoloy representative on the court. Then in early 2048, the court took the extraordinary measure of convening an ex officio "Pan-Corporate Security Committee," comprised of representatives of all the triple-A megacorporations - save for Aztechnology itself - to explore the options open to the megacorporate community. The committee declared that action was necessary to prove to Aztechnology - as an object lesson for the future - that no corporation is beyond the jurisdiction of corporate law. For the greater good of the corporate community as a whole, the committee concluded that the situation required direct action against Aztechnology. [...]
The committee's first task, of course, was to decide precisely what message should be sent of how best to deliver it. [...]

Political favor and reputation. If you show the corp court that you're enthusiastic, you might get some benefit later.

The CC is not some neutral organization which rewards niceness, it's the bargaining table of the AAAs. If you show you're enthusiastic, the competition will still hate your guts and gladly seize upon the fact that you just spent a lot of cash to destroy something instead of strengthening your position by absorbing it.