I was randomly inspired to pick CK2 back up again but I guess some patch had come out and my saves are broken because the main mod I was using is not compatible and whatnot. So I fired up a new game as a custom Doge of Amalfi since that's my wife's most favorite place that we've ever been.
Less than 50 years later I control a good chunk of Italy and I'm married to a Byzantine princess (though I'm no where near strong enough to press that claim yet). I forgot how much bigger retinues can get for a republic and I have a large one, retinue that is, and a nice standing army at my family mansion. I'm also l really, really rich so I can afford mercs as needed.
I've had some pretty lucky breaks so far because there have been a lot of nearby revolts which I have taken advantage of by attacking whichever side was losing or I didn't have a truce with and taking a province here and there. The only thing I really have to worry about there is that I have to win before either side does but it's been mostly easy pickings otherwise.
The only really close call was when I tried to take Rome from the pope. Luckily for me the other Catholic nations took their sweet time before joining in and the Pope surrendered just before their stacks of doom made it to me.