This is your chance to make a civilization that is very different from all of the others. They are wallowing in money, and knowledge, but because they are so focused on money, their military is weak.
Economy
In ancient Nabataea economy was everything! The Nabataeans were a merchant nation, that relied not so much on their military as on the vast amounts of money they made. Incense was the backbone of their economy, although they traded in many items. Rome was addicted to incense. they burned it in thousands of temples, and in every home before their gods. One Roman General almost bankrupted the empire by burning huge amounts of it before a battle. Nero almost bankrupted the empire by burning so much of it at his wife's funeral pyre. It was also used in medicine. It was the equivalent of oil power today. And only the Nabataeans supplied it to Rome, and only twice a year. So whenever a Roman General attacked the Nabataeans, they paid him off. Soon it became very popular in Rome that generals wanted to be posted to the borders of Nabataea so they could "attack them" and get their share of the wealth. Nabataeans traded in EVERYTHING that could make money, including drugs, prostitutes, gems, and selling knowledge. As a people they kept to themselves and did not intermarry, and were very secritive.
Military
General called a Strategos. Main military unit was two archers on a camel. They supplied 2000 of these at the sack of Jerusalem in 70 AD., but they were reluctant to partake in the battle and just watched. They favorite tactic was to ambush people by using their masses of camels to force their opponents towards their hidden foot soldiers and hidden archers.
Temples
(Gods were regional, they accepted the gods of other regions)
El-Uzza: the god of power
El-Dushares: the god of Rocks and Mountains (God of Petra)
El-Kutbe: the god of Writing (Merchants were very clever at writing contracts)
El-Manaat: the goddess of Fate.
El-Qaum: the god of War
El-Lat: the goddess of Fertility (they took multiple wives, women had equal status)
Names
I haved attached a book I have written on the nabataeans.
Character Traits/Ancilaries
Quick to withdraw from battle.
Camels hit hard and leave
Had lots of money, I mean lots and lots of money
Had an excellent spy system, since their merchants lived in all the main cities of Rome, and they had an excellent supply route. They did not visit a city and set up a market, rather, when they came to a city, they went to their Nabataean relatives who lived at that city and dropped of foreign goods, and picked up local goods. They were not above pirating or organized crime as long as they profited. Imagine crossing oil sheiks with Russian mobsters, with Jesuit Priests (who were advisers to kings). Because they traveled and were respected, they knew what was happening everwhere. So they would not have a fog-of-war.
Diplomacy
They were a real democracy, the king (sheik) was elected and was evaluated each year. The usual evaluation was on how much money was being made. In effect, each of the tribes would have an elected leader, then all of these tribal leaders would meet twice a year at the festival in Petra which would be the royal court. They would elect a high king or high shiek. That ruler would lead them for many years, often 40 years or more. Coins (with mroe silver or gold than Roman coins) had the image of the king and his wife on it. The term "King" was used by the Romans to describe the man, but it was not necessarily the term they used for their own elected ruler. What is title was is not cleaer. I would call him the sheik.
Cultural Buildings
Royal Courts in Petra,
Warehouse - for storing all the goods
Treasury - for storing all the money
Tomb with dining hall - Because they were so spread out, they buried all their dead in a burial city (Petra was the main one). they would bring all the bones of the dead and put into a family tomb. They would return twice a year if possible (or every couple of years if far abroad) to visit the dead and eat a meal in the dining hall with all their family and then break the dishes.
Pottery Kiln - for making pottery for smashing at the tombs
Market Place - for selling goods, could be set up anywhere
Caravansaries - stopping places for caravans were put up all over the place, and could be used as mobile HQs where they could fight from, and resupply from. Since they had these and attached families in every major city in the Roman world, they could spawn soldiers from them as well.
If you want to make this game interesting, let the Nabataeans own all the Marketplaces in all of the cities... and they sell to other nations from these, and earn money from other treasuries.
Just an idea.