I'm short of time so i'll be quick atm...
I would suggest merging your forces into 1 army to take the persian royal road settlements from Mazaka to Sardis. They are fairly lightly garrisoned no matter the difficulty level, and they will be your cash cow right from the start. Dont miss grabbing Ankyra for your galatian assault troops. You'll only be in debt a lil w/ this starting strat n fairly soon swimming in $$...and dont forget to put a fort w/ a few units in your East and /SE mountain passes.They can buy u time to raise armies when AS comes for you (they will soon), as well as inflict some nice casualties on em before they get to you. If you can safely hold or sack Antioch early it helps too.