I am currently playing a game as Friesland. My fifth ruler just ascended to the throne and I inherited all my personal unions going instantly from ten provinces to thirty-four provinces. Before this ruler I had directly inherited two Monferrato and Meissen during my first Regency Council. When the current HRE dies, I will become the HRE. I got all my personal unions peacefully except for using the Claim Throne cb on Brunswick, the Fabricate Claim cb on Wurrtemberg, and a Succession War with Bohemia for Luneburg. I have all of my current provinces cored. My second, third, and fourth rulers each had administrative and diplomatic scores of seven or eight, but my current ruler's highest score is a six and my heir's has a military score of eight but low scores for the others. Here is a list of my rulers and the length of their rule:
Willem II 1337-1359
Maurits I de Dampierre 1359-1366
Regency Council 1366-1381
Johan Ernest I de Dampierre 1381-1425
Albrecht II de Dampierre 1425-1448
Willem V de Dampierre 1448-
France's original dynasty died out so they lost cores that they didn't directly own. They were then continuously excommunicated but only now start falling apart. Aragon has four provinces in Greece, the Roman Empire rebelled in Greece after being conquered by the Ottomans, Portugal has provinces in Cyrenaica, and England has Alexandria.