with the baktrians i use the clam aproach i take marakanda and gava haomavarga with proper usage of the lower level phalangitai and then go for kophen the saka are hard to kill but they are diplomatically weaklings so you can normally get peace and a few setlements aslong as you´re not at war with anyone else (i got sulek like that and was able to break their nomadic alliance no allies and having to fight you while they´re your only enemy turns them into pushovers) ofc once you go to war with the seulekids you´re screwed everyone will turn on you i normally do an anphibean attack land around charax and go for babylonia seulekeia and antiocheia once those mics are destroyed and those cities sacked and with every single last building destroying the seulekids can no longer send at you their elites and you get the money needed for the mine upgrades