Faction for new campaign

[Prussian to the Iron]

Saba is a very cool faction, and it offers challenges as well.

Starting Position:

You start out isolated from everyone by rebel cities, and so can expand in any direction without fear of repurcussions for the first 20 turns. You can also land units across the gulf into northwest india, and start pumping out elephants. Ultimately, you have the choice of fighting the inevitably-crumbling seleucids, or the stronger Ptolemaioi. Both offer challenges, but I prefered to take on both at once.

Units:

Some of the best early-game units available, period. They have great non-phalanx spearmen, and their bowmen-spearmen are some of the most flexible, versatile, and useful units in the entire game. You mostly keep them behind the main battle line until they exhaust their ammo, but they can be used to patch up holes in the line and hold them for a sufficient amount of time versus most non-elite units.

[Xurr]

Out of your list you should try the sauro's first, they are incredibly fun. Basically just a way to indulge in a childish killing spree In my sauro campaign I went through all of italy and greece, only using the units that you start the game with, and the only buildings left standing after I left were the ones it's impossible to destroy.

I would suggest baktria though, challenging start, huge unit variety, and the possibility of getting very rich with only a small empire. It makes slow progression and extreme roleplaying very fun.

Yeah Baktria is a good choice. The beginning is challenging with AS sending stack after stack at you. It also offers a nice variety of units and tactics straight off. You get nice phalanxes, awesome heavy cav, horse archers even armored elephants can be gotten fairly easily. The variety of tactics you can employ early in the game makes this one my favorite.

[Maion Maroneios]

Makedonia. Period.

Maion

[Cyclops]

Makedonia. Period....

You associate the Antigonids with the menstrual cycle? Harsh.

Just kidding, Macedon was my favourite (esp. the Agrianes, the solution to almost every problem is more Agrianes) but I OD'd on them and haven't played them since last year.

The OP's choice to take on the Parthians is brave an interesting, something I would find a real challenge.

[mountaingoat]

getai ftw

cheap shock infantry (with some of the best ap in game)

decent spearmen

medium and light cav than can hold

horse archers , elite dacian archers , good skirmishers , and elite horse archers.

you can expand in any direction