Would this have been a better ending? Spoiler, of course.

They all have a fleet including the Iron Born who have the best fleet even at their worst. They are not nearly as defenseless as people pretend they are.

I feel like we are talking around the point.

What would unite 2 or 3 kingdoms to unite to stop one or two other kingdoms who were wanting independence in the first place.

North
Dorne
Iron Islands

All three wanted independence and yet things are now so awesome that they want to stick with the kingdom that killed who they supported, the North is free despite being against the one they supported, but also be OK with NO representation in the new government.

Whatever I guess since the story made it so but it’s not logical even using real world examples that people keep trying to use.