I get Regions without doing anything

[Titus Marcellus Scato]

I don't need "allies" who can't keep their hands out of my wallet. :P
Money is scarce as Saba and I don't want to spend anything on adventures in the North
so early in the campaign.

If Petra or Palmyra has a big army which is costing you money, then roleplay them setting out on their own quest of expansion by attacking the Seleucids or Ptolemies. That will either get most of their army killed off, saving you money, or they'll conquer a city, offsetting their upkeep costs. Or just disband most of their army.