What exactly is the deal here? I've found myself as both King of Lithuania and King of Lithuania. I created a new kingdom as an intrigue decision which was all good. I then had the option to create the de jure Kingdom of Lithuania title, which I didn't bother with since I already had one of them - no one needs two Kingdoms of Lithuania.
Now I die and my son inherits my de jure Kingdom, awesome. But my other son inherits the other Kingdom of Lithuania, created on my death, which is really just the High Chiefdom of Polotsk - a fragment of the original de jure kingdom. Now this was sorted, but there's still two duplicate Kingdoms of Lithuania.
Can the second Kingdom title be destroyed?