We have quite a debacle on our gaming hands:
MC is aware the brother wants to Game of Thrones-Cersey and Jaime make her his golden ticket to the throne, while trying to save her and save himself from totally different pitfalls: he is the patsy/fall guy the brother and senators want to turn into Brutus - while they take the throne, while the sister is trying to pull MC by his sandal straps and up the chain of command to the point he can confidently become Gladiator:
Edit: nevermind, you had answered already
Usually, in AVNs, MC standing up to the abusive, albeit silver-tongued, brother of the LI, is what gives points. We will have to adjust our expectations for this game if things are going on differently behind the scenes.
Troublle is: MC knows he is targeted and his bethrothed is in danger.
(in the fashion of a secret marriage, House of the Dragon-Damon+Rhaenyra Targaryen)
something Maximus only found out when it was too late to do anything but revenge.
How MC becomes Maximus while not losing everything in the meantime ( his biggest supporter - the Emperor, the bar girl who loves him and his servant girl, the princess, and his armies) will be one interesting story.