I like all of this differentiation (example: https://code.wildfiregames.com/D5112 ), but I wish a standard had been set first. For example:
1 general civ bonus (like faster training, stronger buildings, etc. the faster buildings for the Celtic civs comes to mind, or the free walls for the Iberians)
1 team bonus
1 new Forge tech
1 new Civic Center tech
1 new Fortress tech
1 new Barracks or Stable tech
1 new economic tech (at either the market, storehouse, or farmstead; the Harvester tech for the Gauls is a current example here)
1 new tech anywhere (so, a naval tech at the Dock for the Athenians, etc.)
1 new building (a Vineyard or Stoa for the Athenians, a Helot Training Ground for Spartans, etc.); this can be substituted by beefing up one of their current buildings in some way (maybe the Iberian Fortress can upgrade to a Citadel; the Han CC is a good example of this)
Remove 1-2 standard techs from each civ (so maybe Athens gets 1 less farming tech, Persians don't get the barracks health tech, etc.)
1 potential "game changer" bonus: The Marian Reforms for the Romans comes to mind. Not every civ should need this, but maybe 3 or 4 of them should have something on this level, not just the Romans. Maybe the Macedonians can choose between Argead or Antogonid dynasties. Maybe the Han can choose Western or Eastern Han. Just spitballing here.