I think your going to have problems with this idea because the corporation evolved in the first place to route around the stagnation and ineptitude of feudal dynastic government. The two really can't go together as they are antithetical on almost every level.
The central functional core of corporation is voluntary association through negotiated trade. The central functional core of feudalism is forced association through conquest and constant intimidation. Corporations function through meritocratic advancement. Feudalism functions through privileging individuals by lineage regardless of merit. Corporations exist to create and build. Feudalism exist to exploit and destroy.
Game theorist say that corporations are "non-zero sum, win-win" systems in which the system will not work unless both sides of exchange "win" by coming out better than they would have without the exchange. "Non-zero sum" means that for one side to gain something the other side does not have to lose something.
Feudalism is based on "zero-sum, win-lose." The nobles when their station by violently defeating their competitors, one side wins the other loses, for one side to come out better, the other side must come out worse. The same applies to the rest of society. The wealth of the nobles comes from literally taking the food from the mouth of the farming peasants at the point of a sword.
You can't combine two such opposite systems.
Corporations are how Europe escaped feudalism. The verb incorporate means to make many entities into a single one. Originally, this meant merchants and artisans combining to found trading cities, either out on mudflats no one else wanted or by buy "liberties" from the local feudal lord. In England many towns and cities are still called corporations.
As cities began to trade with one another, they found had to manage everything voluntarily because the feudal lords jealously guarded their monopoly to wreck violence on the rest of society under whatever context. They developed a complex set of rules, enforced non-violently, called the Lex Mercator, the merchants law.
Later, it occured to some people that the same type of corporate system used gather resources to build and then manage trading towns could be used for other large projects, like building dykes, canals and trading fleets.
As technology grew more complex and trade grew more far flung, artisans and traders had to survive on merit. The technology did not care for how much pull one had with the local lord and neither did trade partners hundreds of miles away from the lords domains. Individuals could create their products, sail their ships and make deals with people far, far away or they couldn't and it didn't matter who their daddy was or how many connections they had.
In a fast couple of centuries, the people who invested in corporations learn pretty quick to also stop caring about the lineage, religion, class etc of the people who worked for or managed the corporation and started to care about their merit in the task. When you bet the farm on far sea trading venture, you didn't care who the captain's relations were or for that matter how many eyes and feet he had, you just cared if he could sail the damn ship back home at a profit.
By contrast a feudal domain outside the free cities, everything was radically different. An individual could do nothing with a lords a permission and ones family and personal alliances within complex patron-client networks dictated ones personal success in all fields of endeavor. As a result, individuals, families and patron-client network did everything to promote their own, merited or not, while simultaneously tearing everyone else down, warranted or not. Power is zero sum. For one person to gain power, another must lose. There is no win-win in systems dominated by politics.
(Note that in history,the pattern is that pre-corporate societies grew so stagnate and corrupt that they were routinely conquered by "barbarians" with tiny populations and inferior technologies.)
How are you going to combine two system when in one, merit drives promotion and the other actively suppresses it?
Why would anyone voluntarily buy stock, thus giving risking their money in the corporation, when the managers would be chosen purely by birth or occasionally by warfare and murder? The King/CEO in such systems could be a congenital idiot or a 10 year old child. The "company" org chart would be defined by marriages and deaths not proven management skill?
Corporate governance is based on a form of democracy wherein one's vote or say in the company is determined by how much you risk investing. Feudal governance is determined by victory in war of being the descendent of a victor in war. How do you combine those to systems?
I could go on but you get the point. Feudalism and all form non-mericratic, non-democratic, coerced organization cannot be combined with corporations meritocracy, democracy and voluntary associations. Fascist tried it, didn't work. Communist tried it, didn't work. 3rd world Kleptocrats keep trying it. Doesn't work.
But don't let all that history stop you. It certainly doesn't stop anyone else. Every single depiction in every story about corporation you have every seen literally since toddler hood (e.g. everything Disney has made in the last 25+ years that depicts anyone in business at all) has depicted evil corporations and quite often completely unfleshed out, never explained and always utterly implausible evil corporate "governments."
So, I say don't bother to think about it at all. Just mumble something in one line of your story about "Lord Dark Strange, Baron of Marth, CEO of Pangalatic Baby Eaters Inc" and absolutely no one will stop to think about how it would be an utter violation of basic human self interest for anyone to voluntarily thrown their money into such a system knowing that if didn't like how Lord Dark Strange did things, they couldn't do anything about it.
Relax. No writers great or small are starving by shilling this thoughtless trope so neither should you. No one one who writes fiction, screenplays, games, children's shows etc appears to know anything about how corporations work now, much less their history or evolution or what the world was like before them. Corporations are just naturally evil for some vague reason, everybody knows it.
It's a modern writers freebee villain, you don't have to think out a plausible world system of any kind. Just say, "corporation" and bang, instant suspension of disbelief for anything in your story you attach to said "corporation." Having the executives be feudal lords will be a nice stylistic touch that will be swallowed without thought by everyone.