All units should not be balanced. Historicaly some units were just better than others. An armored swored unit is more flexible than an armored spear unit. Historicaly that is how ROme beat KH. They were more flexible. NOw KH can make use of Thesalyian Cav. When fighting against Rome. If it becomes a little more difficult for KH to face a Roman army, than that is better because it is more historicaly accurate.