Be careful with that, as becoming someone's protectorate will cause large sums of mnai to be given from your coffers to your protector's. Just try and avoid becoming a protectorate as much as you can, unless of course you believe you have no other option.
I believe it is quite easy for the Hai to fight back the slow-moving Hellenic phalanxes through guarilla warfare in the Kaukasos and certainly with some of those damn good FM bodyguard units. With a few victories you'll get very experienced troops, so you will be able to use 1-2 3/4 or less stacks to repel any invading Hellenic army.
I have found myself in the same position playing as Makedonia right now, as I've foolishly decided to invade Ioudaia and Syria with an army of mine, in order to pillage every city of the AS (they have won the Syrian wars, confining the Ptolemaioi territories to just Aigyptos). Of course, Ptolemaic oportunists sent small stacks to take back the cities I left undefended, so they immediately declared war upon me. Now I have to fight them both, but I have the advantage of using Hellas as my base of operations, far away from any nearby Successor city.
I wish you lots and lots of fun,
Maion
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