I'm finding it very difficult. Even cheated a little and I'm still struggling lol. I've now got half of Greece unified by 214 BCE, but don't really see how I avoid being crushed between Thrace and Rome. Rome especially - looks like Thrace has peaked already.
The trick initially is to play off different powers against each other, but it can be hard to judge how and when to switch sides. In my game I've variously fought against and alongside Antigonids, Macedonia, Egypt, Thrace, now Taulantia (which has annexed all of Epirus and half of Macedon now). Once you get a decent base, you can also get relatively far with diplomacy. The new tech system has lots of options for extra diplo relations, and there's loads of Greek minors around which it becomes quite easy to diplo-vassalise. And regularly check the vassals of neighbouring powers - if their subject loyalty is low enough, you can often diplo-vassalise them yourself. I think how things turn out with defensive leagues can make a big difference too (e.g. being in a good one helps a lot, but if all your small neighbours are allied, it's a problem).
I've found the mission tree quite difficult and frustrating. Lots of conditions that are very hard to fill, or annoyingly specific (e.g. you need to own Delos directly, not merely have vassalised it, even though the event turns it into a vassal anyway). And now I'm stuck on the Restoring the Delian League tree, where to progress I need to build 100 ships, which I'll never be able to afford at this rate, and annex Amphipholis, Halikarnassos, Sestus - which are not obvious next steps for expansion, and all owned by much stronger powers
I think getting legions early on is a waste of money as well? Greek levies have a pretty strong composition as it is (lots of Heavy Infantry), so you don't gain that much and it's very expensive. Conquering and integrating Macedonian + Thessalian pops is a good idea 'cause they give cavalry, and Lacadaemonians give extra heavy infantry.
Also I think I've crippled myself by not understanding the republic mechanics and accidentally racking up loads of tyranny, so probably try not to do that.
EDIT: Rome just took half of Greece + Macedon from Thrace & Taulantia, then declared war on me. According to the ledger they have 180 cohorts. I have 17. Time to start a new game, I think.
