So, second run (technically third, as I restarted after I messed up the Synhendrion ton Hellenon). Not done, but I think I am.
First off, I though it would be a smart move to go for Sicily pretty soon. It wasn't. Syracuse bloody hates me, I can barely keep the order up with a temple of Zeus (good time to start using temples of fun I guess) and it will start rebelling as soon as I enter the Popular Revolts stage of the government reform that I found myself delaying at the end. Pergamon is also feeling pretty balsy right now, advancing on Macedonia. My economy and national safety would have been MUCH better if I prioritized taking them down rather than Syracuse that and south Italy that stuck me into an inconclusive war with Rome and Carthage. So, in conclusion, don't move West until you secured East.
Second off, the trait system absolutely ruined me. Almost half of my generals ended up outcasts and/or terrible governors for acquiring bad faction-exclusive traits that I don't think I really have any control over. I think that's the biggest strategical burden KH has to face on the campaign, that you will struggle to get decent generals and governors, and loyalty will be rare even on the early stages of the campaign. Do consider having spies in your armies to reduce odds of rebellion. Their successful missions should also help out your FL to get some authority. And don't fret too much about the Archons, you will probably have plenty of candidates when you actually need them. And, in my opinion, Athens and Sparta are still the best candidates for Sympoliteia Hellenon to get another option to reinforce your Cretan mercs.
I think I will give em some rest now and try another Hellenic faction. Maybe Pergamon, maybe Bosphoros, maybe a small successor state.