I don't know if this would cause model issues, but I was thinking, would it not be realistic if Makedon and Epiros recruit pantodapoi phalagnitai in the east, and Arche, Ptolemaioi and Baktria recruit Phalangitai Deuteroi in Hellas. Also, maybe the Qarthadastim, on conquering Greece, should have acces to some sort of pike, which they used in large, mercenary quantities, so surely if they conquered Hellas then they would recruit pike from the local population?