I personally never use theurophoroi to pin down phalanx units, and only rarely will I use them to pin down units of hoplites. This kind of matchup really doesn't play to their strengths I find. Instead I find this unit is an expert at hunting down enemy cavalry, being more versitile and quicker then phalanxes or hoplites but still keeping a bonus against cavalry. They make great flankers early in game, being able to slip around the flanks and engage the enemy from behind rapidly. Against sword infantry, skirmishers, and levy hoplites they pack a nice punch.