And if Hanse finds evidence of Baron RIcky selling (Or allowing them to be sold if he doesn't personally own the plant, which some stuff would suggest) 'Mechs to pirates, the CC or DCMS, how long until he shows up with the entire Davion Brigade of Guards to 'discuss' the mater with Baron Ricky?
Baron Ricky needs to not be a dumbass if he wants to keep his position.
It's all political gamesmanship. The nobility want to keep their power. They joined up with the Great House ages ago because it offered protection against the other Great Houses. Baron Ricky doesn't want to face down the might of the Draconis Combine with just his little mudball planet. So you join up with a more powerful nation, on the condition that you remain ruler of your little corner of the galaxy. And all the other guys like you want to make sure that Big Bad Hanse doesn't think he can just throw his weight around and take what is rightfully theirs. It's almost like being members of a union. All the little guys band together to prevent the factory owner from cutting wages and showing everyone the door. But you have to pick your battles. If Billy Bob shows up to work drunk and accidentally knocks someone into the grinding machine again, well maybe the union tells him he's on his own this time. You're not gonna stick your neck out for that guy. Same with Baron Ricky. The nobles make a case-by-case determination as far as when resistance to the House government is appropriate.
But we really aren't talking about someone supplying pirates with mechs, or an enemy state. We're talking about selling them to people who are citizens of the realm and hold some degree of local political power.
So at the top level, you've got the leader of the empire. And this person has control over the assets of the state. There'll be official FedSuns (or FWL, or Combine, or whatever) units that are basically national-level forces. They are like the US Army today, whoever is officially in charge of the country has command over these units. But ti doesn't stop there. The leader also has their own private armies. These are forces that the leader owns outright. Even if he wasn't in charge of the country, these forces would still report to him. And he probably has several layers of forces like this. Hanse Davion wasn't just First Prince of the Federated Suns, he's also (as I recall) the Duke of New Avalon. And he's probably the major shareholder of a dozen different companies, each with their own private mech forces. And he has other titles on half a dozen worlds, and has direct command over their forces as well. And then he's got agreements with other nobles, for them to provide a certain number of regiments to be at his disposal whenever he wants, up to a certain number of months every so many years. And then he's got mercenary regiments that he's hired with his personal wealth, and then some he's hired as Duke of New Avalon, and then some he's hired as First Prince. All told, he's a fantastically powerful man.
And then under him, he's got half a dozen Grand Dukes (or whoever, I forget the exact breakdown of how their nobility is structured). And each of those guys is almost as personally wealthy as Hanse. They have their own long list of titles from various planets. They have their own companies they control. They have their own private armies, and they have their own people who have pledged support to them. And while they don't have direct authority over the armies of the Federated Suns (that goes with the position of First Prince), together they are probably more powerful than Hanse (that's why he keeps some of them as very close buddies).
And then under those guys, you have the nobles who rule just a few planets. Duke Whatshisface rules one kinda important planet and like four planets that are crap. By a normal person's standards he's incredibly wealthy and powerful, but to the other nobles he's kind of a joke. But there's like 80 guys like him across the nation, so together they're really important. And this guy is still Bill Gates rich, no question. And he's got like 3 regiments that support him, so he's dug in really deep, and getting rid of him is going to take real commitment.
And below
that guy, you've got the Marquis de Doofusville, and 4 or 5 other guys just like him. The Marquis is the most important guy on one particular planet, even though there's nothing really important there. And he's got a full battalion of mechs, even though a lot of them are in pretty crappy shape, and some of them only kinda exist on paper.
And under
him, you've got Count Steve, and under him, Baron Ricky. In the grand scheme of things, Baron Ricky is a nobody. And no one is going to shed a tear if Baron Ricky does something stupid and gets replaced. But also, every other noble in the realm is watching to see if Hanse Davion starts taking undue advantage of the little guy. Because every single one of them is making use of private mech owners to supplement their forces.
So at the top, there's Hanse, and he's the most powerful. But if the Grand Dukes under him teamed up, they're stronger than him. And if the regular Dukes under them teamed up, they're more powerful than the Grand Dukes. And if all the Marquises (had to look up the plural on that one) teamed up, they're more powerful than the Dukes. And so on down the chain. The guys below you have enough power where if they all get mad, they can overthrow you. And at the very bottom, you've got some dude who owns a Shadow Hawk. And you sort of have to share the wealth with the guys underneath you, to keep them happy. Baron Ricky can't afford to piss off the individual mech owners, because together they have a bigger army than he does.