The Thureophoroi of Illyria, are lighter armored than their Hellenic counterparts, but as good against phallanxes.
Lighter than the Hellenic Hoplites, that they used to fight, and equipped with a different shield, a deffinite Keltoi influence, the Illyrioi Thureophoroi, can hold the line, if needed, but their role was to harass rather than fight, and shower the enemy with spears from afar, not go up against it. At this they excell, as it is the very lack of armor which makes them very agile. Only their bronze Illyrian helmet can be considered armor as well as their thrureos shield. They carry a healty amount of javelins which they throw at the enemy but when it comes to close action with their spears, they leave a lot to be desired.
Historically, Illyrioi were hammered by the same force that destroyed Makedonia and killed its king, Keraunos: the Keltoi. As one of the nations to border with them, the Boii nation of them, they did use a lot of their methods in fighting and mixing with their own peltasts, a heavier version was created, the Thureophoroi. While lighter than Hellenic Thureophoroi, they are as good as them or even better when it comes to harassing the enemy and especially pike phallanxes.