In my Seleukid campaign I tend to use them a lot in conjunction with Peltastai, light infantry (such as eastern axemen), and prodromoi, so I have quite a mobile army. I send the thureophoroi and peltastai to the flanks (and with their spears they get advantage vs enemy cavalry), while the thorakitai attack from the front. Once the thorakitai have locked the enemy in place, and the peltastai and thureophoroi have spent all of their javelins, and enemy cavalry have been taken care of (for this generally a thureophoroi aided by the prodromoi), I chargee!! This generally collapses the enemy flanks and I'm free to move against the center, which most of the time is a brawl between my own phalanxes and the enemy phalanxes.