Evrart and Pryce are both probably jumping for joy over what happened in Martinaise. Unless you know about Dros and all the other little details, here's what the Tribunal looks like to an outside party:
A group of Union men hang a mercenary, sent as part of a strikebreaking measure by a foreign military contractor. The police don't show up for a week, and when they do, they don't arrest anyone. Instead, two policemen stand between the rest of the mercenaries and the Union men and defend them with their lives.
This is an incredible look for the RCM.
If your population thinks you've been licking the boot of foreign powers at the expense of your country, this is probably the single best way to convince everyone that, actually, you will stand with the common people over those that would exploit them. But just as much as this is a good look for the RCM, it’s also a good look for the Union.
Remember, one of the problems that the Union is going to face once they manage to kick Wild Pines out is that people will pull from doing business with them. Just as the Moralintern once afforded RCM legitimacy, the RCM, a kind of governmental body, can provide some guarantee that the Union is still all above board and safe to ship with, thank you. Obviously, there will still be concern and many international corporations will pull business, but the illusion of RCM approval and oversight could be a comfort, especially if the Clare brothers know how to play it (which they do.)
A shallow alliance between the RCM and the Union is inevitable, I think, maybe even a deeper one considering that the RCM is underfunded and the Union is about to come into a lot of money. That being said, I can’t imagine the relationship between the RCM and the Union is going to be any less contentions that the one between the RCM and Moralintern. Pryce is going to learn from Harry about what happened to the last Union leader before the Claries took over. I don't think he's above holding that knowledge over Edgar and Evrart's heads.