Haven't played MP yet because I don't want to be a nooblet due to the new controls. But in the custom battles screen I can see some limitations: elephants and chariots are limited to 2 per army for example.

Also, Parthia has IMO the best roster out there, followed by Rome, Egypt, Macedon, Epirus and Carthage. The Suebi have some pretty badass looking melee infantry and I think they can grind down pike spammers (haven't tried it yet).

If push comes to shove and all you see are pikemen just spam pretorians with armour upgrades. In Rome 1, Urbans could charge right through any pike/spear unit and grind their faces in with their gladii.