It was a classic match up between Michael's Athenians and Steve's Spartans. Michael set up terrain, placing two large woods a large marsh and a large area of rough going.
After the game, the Steve posed the following questions and comments (in Italics). My responses follow.
A comment regarding the lists. The Spartans were able to field two Hippeis and a Thracian horse, which was exactly the same as the Athenians. Should the Spartans have a restriction re mercenary cavalry or did they really field as much as the other Greek states?
Regarding cavalry, with the exception of some of the northern poleis, Peloponnesian states (generally allies of Sparta) had as good a potential to field mounted troops as their opponents, even if Sparta itself never fielded very many. Boiotians tended to field better cavalry than southern Greeks (and more of it), the Thessalians were the best mounted Greeks of course and were almost on par with the Macedonians.
Depending on the theatre of the war, Spartans might have Greek allied cavalry from the Peloponnese, from central Greece, from the Greek cities in Thrace or Asia Minor etc so there's no real issue with a Spartan led force running multiple cavalry companies.
During the game, the Spartan hoplites advanced through and fought in the terrain as they still had the advantage over the Athenian light troops. We were unsure as to whether this was your intention.
In short, no. The balance that will have to be achieved (through play testing) is how to to treat Hoplites. In rough terrain they already drop their movement down to 1" per turn, so Michael's peltasts should theoretically have been able to skip around flanks and pepper you with javelins.
Perhaps a further melee modifier is needed for hoplite companies; maybe -1 in rough and -2 in woods?