The thing about the Lusotana army is that their stats do not conform with the cost effectiveness. For like in online battles then nobody plays as them, but people either pick Gauls or Carthage to be the 'Barbarian' army.

Carthage has a better unit roster than the Lusotana, for the Carthage receive all the good Lusotana units but none of their bad units. Like Iberian assault infantry is the upgraded version of the Loricati scutari and the Elite african infantry are the upgraded version of the Dunamica.

The Best Lusoatan units are propably:

Asturian axemen as the heaviest AP unit.

Dunamica/Scortamareva as the best line-holders.

Iberian scutari as the best flankers.

Lusotana light infantry should also be good for they have both AP attack and 6 javelins, so they can use their swords against heavy opponents (Rome, Greeks) and their javelins against the light opponents (like Gauls).

If you ask me then I think that the Averni and Carthage should rather be picked. Gauls can employ Rhaetix axemen whom are better than asturian axemen, Milnaht/Neitos whom are better than Illergetan soldiers, Alpine phalanx/Mori gaesum as a flankers. But alas, Iberian scutari are my favourite but belong to the wrong faction.