When one of your vassalt revolt (either for independence, install a claimant or depose his liege), its kinda irritating that while some vassals join his plot, others who love their king or simply hate the rebels a lot just stand there and watch how it goes. It would make more sense if "loyalists" vassals would raise their own troops to lay waste on the rebels, especely thoses who live at the border of ennemy countrys that might decide to invade them at the same time. They would be motivated for their own defense to end the rebellion faster.
On the other hand, you could have ambitious vassals joining the war in hope they you will reward them with land revoked from the rebels, like a count deciding to swear allegiance to his king instead of his rebelling liege duke in hope of getting the duchy for himself or a neighboaring duke eyeing some juicy land.
And youd have thoses who join simply for their loyalty to their liege or simply to mess up their neightboar that they hate with a passion.
Of course there would be also thoses who stay neutral like they are all doing at the moment if they have no real interest in the conflict (like they like/hate the king as much as the rebels) but it would make rebellions more dynamic.
On the other hand, you could have ambitious vassals joining the war in hope they you will reward them with land revoked from the rebels, like a count deciding to swear allegiance to his king instead of his rebelling liege duke in hope of getting the duchy for himself or a neighboaring duke eyeing some juicy land.
And youd have thoses who join simply for their loyalty to their liege or simply to mess up their neightboar that they hate with a passion.
Of course there would be also thoses who stay neutral like they are all doing at the moment if they have no real interest in the conflict (like they like/hate the king as much as the rebels) but it would make rebellions more dynamic.