in my opinion about formations, you just need
1x general
2x Eqvites (or Extraordinarii), placed on their Wings
2x Velites (loose formation, on the front without skirmish mode)
1x Missile Troops (Sphendonetai is best, but Mistophoroi Toxotai Kretikoi or Sotaroas aslo works)
4x Hastati
4x Principes
2x Triarii (remember they are supposed to be half-strength)
2x Pedites Extraordinarii (or another local Heavy Infantry) on the wings
2x Hoplitai Haploi, or some kind of cheap local troops helping the Triarii