How do I stop a hundred-year line of conquerors?

For one hundred years Scandinavia has had conqueror leaders. It's not necessarily parent to child, as they have an elective succession system, but whoever wins, related or not, gets the trait conqueror.

I can't wait for them to die for partition as one man gets all, and at this rate where it seems it'll just keep going, it's a matter of time before they take down my empire as they are eating the rest of Europe, there's literally nobody left but me and them in Europe.

I can't murder them, but even if I did the next guy would just get it. What? Why? How to stop?

Also is this a glitch? I feel like this shouldn't happen, right?