It seems to me at first glance that the start is post-Imperial without villagers, we need to capture buildings. This means that the buildings are originally owned by Gaia and then it converts from player to player. From the game I saw, the buildings were also looking to be in Imperial Age by design. This means that Conscription, Hoardings, Masonry, Architecture and every other tech in full tech tree mode is researched. Good.
But since these buildings were originally built by Gaia, my work rate bonuses won’t apply. Frank Chivalry, Hun, Briton, Goth, Celt Team bonus and Goth Perfusion are useless now. On the other hand, creation speed bonuses like those of Aztecs, Cumans, Turks work fine. Add to that Lithuanians faster working monasteries are also stripped, which means Lithuanians may struggle (lack of relics, hard to get castles, not much bonuses).
I am not sure about water component, but Persians will suffer if there is water. They don’t have Shipwright. The offset was them having naturally faster working docks per Age, which was quite worse in Post Imperial. Shipwright was a creation speed bonus whereas Persian bonus was a work rate bonus. It was 20% vs 53%. Well now make it 0% vs 53%.
Portuguese may get better than what they were in 1vs1 Arabia. They had 1 relevant bonus then (20% cheaper gold units), now they have another in Arquebus.
Mayans may also lack due to poor siege and their key unit being limited to castle. But they have Obsidian arrows, best Eagles in game and now Xolotl Warrior which may be handy in a pinch. The idea is, they won’t be top tier anymore.
I may have missed to mention some bonuses which may not work. If you think one, please mention them.
Oh that’s interesting. Alternatively, when converted villagers are retasked or monks made to pick up a relic, they will receive any improvement you have the original owner lacked, so maybe there would be some way to apply it to buildings?
Gaia’s “civ” is just here to determine the architectural set, and the fact the scenario editor would display “Sarracen” by default is because they needed to have something there I suppose, just like player 1 would be Britons and player 2 would be Frank and so on.
It is a simple but interesting game mechanic. The game is basically replacing one unit with another. If you convert a forager and task it to wood, it will become a lumberjack, which is different. To do this, the game actually replaces a converted unit with your own unit. A similar mechanic happens with Trebuchets and monks picking up relics.
Outside of these, there is one weird exception which is siege units. Basically siege unit upgrades and siege engineers upgrade changes the stats of converted siege units too.
Another thing about Gaia civ (not the Gaia market) is the trade inefficiency is 0% which means that if selling at buying price at markets is the same. The Saracens have 5%. Other civs have 30% and guilds brings it down to 15%.