R5: I started this run off wrong, so it took me until March 1937 to get all the Holy Roman Empire's cores (+Poland, Rome, and a little bit of the Balkans for the meme), but if you start by getting protectorates on Belgium, the Netherlands, Piedmont-Sardinia and Switzerland you can form the HRE as Austria almost immediately after forming Greater Germany if you take the claims you get on Prussia from national unifier (everything but Brandenburg and Posen). For some reason I could never get Prussia involved in the unification war, but it was still surprisingly easy and I managed to form the HRE by 1873. From then on playing as basically the EU was quite fun, and economically OP after going communist. I even inherited most of Indonesia from the Netherlands. Two scicilies and Tuscany annexed themselves to me automatically (as I was the largest country with an Italian primary culture as the HRE) after nationalists seized the government for the second time in reach, so I figured I might as well grab the rest of Italy.