If you looking for best mix of units, then go for Makedons. Hippeis Thessalikoi owns all other cavalry around there, phalanxs are toughest ones and generaly you get great mix of units. They do get best cavalry and infantry around.

Plus as bonus you get to destroy KH in beggining(same as Alexander Makedon), which is a quite enjoyment.

You have so many options with them. Offensive army, they got units for that. Defensive army, they got that. You can basicaly have 3-4 elite armies with all different units they get down the road.

In my campaign i was fielding all regional Gaul army recruited in Tylis and Singidunum on Balkans , All HA army around Black Sea and regular Makedon "hammer and anvil" army in Hellenic areas.And , none of them was weak.

That was in 208 BC though , so could take time.

Other then that i liked Casse units (nasty guys with 2h hammers and 2h swords are really rockin). No good cavalry till 220BC though.