alkright its fairly easy tbh,
If u are makedon or greek factions itll be fairy easy,
move_char ur char into pergamon and conquear it, then use money cheats (add_money) and process_cq to put some happiness building and the city wall then u gift it along with some money to epiros and transfer whateveer character is left in greece to there
then get a ceasfire for 5 years
after that you go and conquear there homelands and create alliance with rome, sooner or later epiros will get killed in rome and theres your pergamon kingdom...
If u want to delay rome and carthage, you can also use the same trick on syracuse and build up hapipness and crap (port too)
then gift it to koinon hellenon and move 1 character (or w.e there)
then conquear greece! wallah you got a syracusen kingdomthats fighting rome and carthage !! or u can transfer tthem to massalia/emporion/arse to make the hellenic migrants tehre