In my experience playing Hellenic armies (KH, Baktria, Maks) I have found the Theurophoroi to be solid cheap units. They don't cost a lot, and I expect them to suffer 50% casualties. If you want solid line infantry, you will have wait until you get Thoraktai (if you are a faction that gets them). Otherwise, you are stuck with the limitations of your faction MICs. I myself find that Hoplites (classical and even FM bodyguard) do not fare well against phalanxes. They make great heavy infantry, but used frontally against Phalanxes even the toughest hoplites get chewed up. I tend to use hoplite phalanxes (non-phalanx despite the name) in my current KH campaign to try to counter what the Maks, Epirotes and AS throw my way. You might want to try them out as mercenaries...