empire stability is dependent on population not just number of cities. I will rewrite the guide since its out of date.
do you have any saves?
Population by province type:
- Core: 40 (6 cities)
- Green: 25 (4 cities)
- Yellow: 14 (2 cities)
Stability score:
Civics (0) - Empire/Tribal Custom/Slavery/Descentralization/DC
HH (-1) - two cities unhappy, coherent, I suppose
Economy (-1) - no idea about the score
Empire (0) - it's fine, I reviewed it now, coherent with my geographic expansion, I suppose
Religion (-1) - only two cities have one religion - I'm using dynastic cult...how can I turn it to zero?
At this state, if I get two techs from the Armenians, my empire collapses. I was expecting at most a instability period, anarchy, but not collapsing (maybe because I don't fully understand stability mechanics).
BUT...
If I wait next turn, one city (Arse) is no more unhappy, the HH turns zero, but I still collapse if I trade
two techs: I found that my stability score worsens if I get
one tech - then, when I get the second tech with another guy, the empire collapses. Is this supposed to happen?