Not everything that can be separate beliefs should be. In fact, when the beliefs are about the same object, I think they shouldn’t be; you want your beliefs to have different focuses so you have more than a one-track character. And these are all intertwined; you can’t put him on the throne if he’s not protected, you don’t want to if he doesn’t know how to rule, there’s no point in teaching him if he’s either dead or not ruling. It’s one big, multi-step belief, but it has a single core idea: making the untried prince into a good ruler.
You can say “No matter the price!” if you want, but it still doesn’t mean anything. What would make it really good is if you named the specific price. Even if it brings my family to ruin, even if it costs my good name, even if it leaves the kingdom in ashes, even if it costs me the queen mother’s respect, whatever. But that’s not necessary. I’m not of the Luke Crane school of pushing characters until they scream and weep blood. Sometimes you want a happy and heroic game. Sometimes it can be about seeing the extraordinary effort characters will put in rather than how much you can hurt them.