GoatsHeadSoup
Chieftain
The loyalty penalty alone is enough to make Dark Ages hard to swallow. With a 7 governor cap, it's going to be very hard to deal with a dark age if you've gone wide. Border cities will be flipping faster than burgers at McDonald's.
Also, some of the dedication bonuses for Golden Ages are insanely OP too. I'm thinking that weaving Dark Age-Heroic Age to get the triple dedication might be better than aiming for back to back Golden Ages.
This is actually a great way of balancing dark ages, for human players at least. I guarantee that the AI is not going to be able to handle this very well. On lower difficulties the AI will probably get stuck in a permanent dark age due to how far ahead the player is, and on higher difficulties it will be in a permanent golden age because of how much the AI cheats. It will be interesting to see how this eventually gets balanced.