Looking at the balance and differences between archer, slinger and peltast civs there should be something like a peltast "buff" for civilisations Athens/Sparta/Macedonian - so that they could have something like archery tradition but for skirmishers - this doesn't need to buff the strength of the attack but rather make them run faster (or as fast as they did in a23) and lover the training time for 10% - the cost of this could be something like 400 food - and this would differentiate peltast from