I asked about Triarii stats some time ago and this is what I was told:
Quote Originally Posted by MarcusAureliusAntoninus
About the Triarii.
The Polybian Triarii is statistically better than the Camilian Triarii. The old reason for this was that the Polybian triarii had mobility to make up for the stat loss. But now that the Camilian Triarii has the overhand animation, they are essensially equally mobile. Should not the stats be changed to about equal...?
They're pretty much equal as it is, the only difference is that the Camillan version has a very slightly better lethality, as it should be. Thank you for drawing attention to these, though, I noticed that the Polybians have a wrong shield rating.
The Polybian has a greater advantage fighting cavalry as well. Cheaper too.