I found an important abstraction of how to approach any leader, imho. Find what they're good at and focus on that, haha.
Anyway, for Charlemagne, that means defense, REXing, and walls/castles/engineering, along with the CoL.
The first technology for Charlemagne (assumedly of HRE, and not unrestricted leaders) should be archery. The first build should be a settler. Before finishing the settler, build an archer to escort the helpless fellow. This will create at least a 6 defensive ability in the second city within the first 80 turns. For the second technology, focus on food of course, but try to get to the Oracle if at all possible.
I am about to win as old Charliehorse on a Diplomation victory, though it is on a standard map, which is of course noticeably easier.
I was able to bring the Pericles/Justinian block into my sphere of influence by Oracleing CoL first, and converting him to Confucianism. Pacal has been a pain in my ass all game, but I will soon win a diplomatic victory on account of my vassals, and my soon to be conversion to US.
What do y'all think? Did I just have an easy start since I didn't need to worry about fogbusting on a small island, or am I improving? Charlemagne is my favorite leader, though he is difficult.