What now?

[FriendlyFire]

Thing is, a lot of the very basic units are actually pretty good handled right. Classical Hoplites, Hellenic Heavy Skirmishers, any slingers with some experience, Gallic Light Cavalry to name but a few who are disproportionately good for their cost.

Huge agreement on this. In my Hayasdan armies right now I have classical and Persian hoplites, levy phalangites, Scythian riders, Georgian swordsmen, and various local flavors of archers, spearmen, and axemen. All less than 400 Mnai upkeep, and they're stomping the Greeks quite handily. If Baktria or the Ptolemaioi ever get serious then I might spurge on some mercenary phalangites (>500 Mnai upkeep, the horror!), but apart from that I'll stay cheap - and save up for a Royal Cataphract Army

Also is there any trait related to the Agoge in Sparte? If there is how can i get it?

As noted above you'll be told when a new family member comes of age that he can attend the Agoge in Sparte. Basically, he has to get there before he's 20, and then stay there for 4 years. Completing the Agoge normally gives your general +1 influence and +1 morale for his troops, which seems a pretty poor return for 4 years of his life. But you might have someone who excels (+2/+2), or even someone who gets invited to join the Spartan "secret police". And if you build up a good academy in Sparte then your militaristic types can do their studying and get ancillaries while at the Agoge, while your wimpy bureaucrats can do the same in Athens.