If I was a Celtic general, I would counter your Thureophoroi army with Milites Ilergetum (5), Dunaminica, (5) Gaesatae (1) and Carnute Cingetos (1).

After my Iaosatae (2) have thrown all their stones I will advance my infantry in two lines. I have Remi Mairepos cavalry (4) to counter any of your cavalry and protect my flanks.

First line I will position my Milites Ilergetum to face your Thureophoroi. You will kill off many of them sure, but they are fodder. They are better than Bataroas because they carry an extra javelin and have better defense and only a tiny bit more expensive. Once in melee you may find yourselves at a disadvantage though because they are skilled with longswords. Your Thureophoroi will probably beat them off but just barely. I also have a Gaesatae to scare your men and Carnute Cingetos to inspire mine. My next line I will advance the Dunaminica forward to throw its javelins. Not only do they have the same number as your Thureophoroi, they are armor piercing. So you will definitely take casualties, and I am not aiming at your depleted Thureophoroi that threw all its javelins and fought off my Milites Ilergetum. My Gaesatae and Carnute Cingetos have taken positions on either flank out of range from your Thureophoroi and protected by cavalry by my Remi Mairepos. As my Dunaminica start shredding apart your Thureophoroi. I move my Gaesatae and Carnute Cingetos close to prepare to flank. My cavalry is screening them to get your cavalry to attack me. My Iaosatae are in reserve on the flanks too standing as light infantry. Any Milites Ilergetum that have regrouped have also been put on the flanks. At just the right moment I charge your cavalry to tie them up. Then my Gaesatae and Carnute Cingetos are come around your sides, throw their javelins at your Thureophoroi's backs, and charge with the remnant Milites Ilergetum and Iaosatae. After the fog has settled, the Greeks remember that they are not as brave or as stout as the mighty Celts are in close combat. Only through tight formations of hoplites do Greeks stand any chance against the skill and ferocity of Celts.