It's excellent thread.

Surprisingly bad: cohors reformata and imperatoria.

These are boys to beat by all: they are more numbered than typical medium opponent unit but without chevrons they perform quite poorly - nothing to do with famous legionaries efficiency.

So indeed making any comparisons to them has little value, they are not good reference.

Surprisingly good:
Iberi Scutari


These guys are not that expensive - 1785 mnai, and have decent stats, but somehow they beat many other units of better stats, and perform overall better than many theoretically better units from Carthaginian or Lusotannan roster.

For example they can beat most units costing about 2000 mnai, medium phalanx 1 on 1 from the front (if they have access to their sides), and then they kill many % of expensive elites before they die or rout.
In some cases they perform better against elite infantry than theoretically more suitable (and expensive) Iberian Assault Infantry (for ex against Inf Guild Warriors - Baktria).

Indeed they perform better than expected against any type of troops, and being spearmen they are suitable against cavalry and chariots. On top of that they are fast moving to chase units and do not get exhausted quickly like heavy units, which is important in crucial moments.

All this makes them very versatile infantry suitable for any role on battlefield.
Their main weakness is vulnerability on missiles (they don't have heavy armor) and then perhaps not the highest morale. But after all - they are not elite.

Another good:
Iberian Assault Infantry


Exclusively Carthaginian unit. Again excellent ratio: price/effectiveness.

They beat most infantry units available in the game, for example any roman infantry unit 1 on 1, all phalanxes units 1 on1 (if they have access to their sides). Only most expensive infantry elites can beat them, but it means it must be much more expensive infantry than 2239 mnai.
They are good against missiles because of armor.

Their weaknesses are: - they got exhausted quickly as heavy inf, they must avoid chariots and they are less effective against cav then spearmen.
The best use is against infantry lines of any type.