Hospitals and oil wells: hospitals will take over the healing function previously served by temples, while oil will be introduced as a new resource. Oil deposits will be distributed across the map, and a "shale oil extraction" technology could be implemented, allowing for oil to be extracted anywhere, albeit at a higher cost.

Which is a huge misconception this game also incurs, as explained in Thoughts on the Athenians :P. That they were good at sea doesn't mean regarding their "marines", but their fast ramming ships used to disable enemy ones, which, ironically, needed to have the least amount possible of deck soldiers to be swift. Thus, not only there's nothing characteristic about them, but they didn't rely on them and used as few as possible (so having them as a "champion" Athenian unit is as misleading as it could be, and why I proposed the Tachunautousa Triērēs instead). The real secret of Athenian success at sea was not just how ships were lightly built, but their expert oarsmen, drawn mostly from the low thḗtēs class, who would train all their lives expecting to be good enough to be selected by some trierarch to man the oars of a navy vital for Athens, which brought them prestige, thus more leverage and participation, in their nascent democratic system.

I have included some of the structures from this into the game.

I agree with that. It should be something that exists to provide greater immersion. +++   On the other hand, I've considered training marines on ships, similar to how the Athenian marines already operate, but aside from some bonuses, I don't know how to make it work. http://amodelcastillo.blogspot.com/2018/03/la-armada-imperial-de-roma-rangos-y.html?m=1   Milites Classiarii for example.   We also have the Nautae They are ordinary sailors; they too participated in the combat.

I don’t have a standalone mod specifically for bots, though I did previously upload some tweaked bots to the forum, they’re quite outdated now, though still playable with a few minor fixes. They do have quite a few flaws, however. That said, in the mod I’m currently working on, I’m incorporating the successful features from those earlier bots into an entirely new one. It will include various behavioral modes, pre-loaded tactics along with a few "dirty tricks" if I come up with any, and a degree of randomness in its actions to ensure it doesn’t feel too predictable or formulaic. That’s right, I started a thread about AI quite a while ago, where I’ve been uploading those bots.