For anyone interested, my Pontos campaign was fun from the start. At various points I had to make decisions where to strike next. There was a moment when I neighboured 7 factions yet I had an army in Crimea, ready to attack Sauromatae who did nothing to me. Stupid, so I returned with 3 Polemon diplomats. At the time, I had taken all Seleucid possesions of Asia Minor, plus all Eleutheroi ones besides Ankyra (became Arverni) and that city to the south-east of Trapezous, which was taken by Hai. Ankara (Arverni) and Halikarnassos (KH) were very well defended, especially the latter with almost 2 stacks. Byzantium was Epirote, Pergamon was taken by Macedon, Side was still Ptolemean and Tarsos still Seleucid. At that point I was fighting only with Seleucids. In the end I decided to take Side, then Tarsos, then Antiocheia, anchor there my defence and move later to the east, first Ankyra and then either Greeks or Byzantium. Dozens of turns later, Epirus was killed by Macedons, KH accidentally by me (they had a city in Crimea but no FMs), I took Ankyra and Arverni asked for ceasefire years later, Hai still peaceful and allied (and strengthened), but I am now fighting in 2 fronts with the 3 strongest factions in the map. At least I am alive and, thanks to the AI stupidity and mines (on average 900 mnai per settlement, or 18k for 20 cities), I can feel safe despite the austerity and the multiple threats.
For the record, in my opening moves I started by going north against eleutheroi Sinope, then Trapezous, then I hardly managed to get Nikaia and keep it with several heroic victories against eleutheroi and Seleucids, then waited and defended in fear of destruction, then Mazaka and the other Seleucid cities phew.
I quickly tried several factions already while learning; Sweboz campaign is pretty easy (I blitzed until I had 7 cities, then rested, then got a few more and then I got Casse), Bactrian one is tricky early, Carthage start is easy. Lusotannans have the best feeling (perhaps it is merely the color, or the safe location). My next one will be a journey to India, perhaps as AS or another try as Bactria.