Problems? The Romans actually have good cavalry. I just ran the archers down. Even pre-Marius, you can get Legionary cavalry. After Marius, the Praetorian cavalry is one of the most powerful in the game. Equites and Roman cavalry are both serviceable, cheap cavalry.

Archery isn't overly effective, for me. If you shoot armored hoplites or even standard hoplites, they take few casualties with every volley. Against armored hoplites, even Cretan archers have trouble killing them. What they are very effective against are unarmored targets. Armored targets don't take much casualties.