Specifically, "Across the Ages: Mediterranean", which would be modeled after the Mediterranean taking aspects of Mesopotamia, Rise of Rome, Fall of Rome, The Middle Ages, Age of Discovery, and even the Napoleonic Era...while expanding it to also include all the tech from the normal game through the modern age, so while we're at it throwing in the WWII scenario, too.
There are some obvious hurdles.
The first being, is it easier to start from scratch, or to start from the Rise of Rome scenario (since the seven player civs with the eighth being canon fodder Egypt are from said scenario, but for good reason) and basically nuke the hell out of many key aspects of it.
Like...literally every single tech, and redoing everything involving the techs...which means, everything. (Notably, this would not be replacing my existing scenario; this would be a project undertaken separate from it which would also take things in a different overall direction; things in my current scenario, while mostly kept in, wouldn't all be kept in.)
And if it's easier to start from the Rise of Rome scenario...if it's possible to change the map to the maximum possible size (I am fairly certain the map isn't maximum size in that scenario), keep the lack of edge-wrapping all scenarios feature, and then add in resources to the appropriate spots from the other scenarios, add in resources from the standard game in locations where I'm employing guesswork (unless I cheat and look at a "map of the world" scenario, I suppose, of which there are dozens preloaded), add cities in, and so on and so forth and whatnot.
My basic idea here is that the Celts both represent themselves, and also pieces of the Franks/French and English; the Goths represent themselves, descendants in the form of Ostrogoths and Visigoths, a little bit of the Franks/French and English (via the Anglo-Saxons), the Germans, the "Viking" civilizations (Sweden, Denmark, etc.), even Russia.
The Scythians would be renamed the Mongols, representing said civ plus the Scythians and Huns.
The Persians represent a sum of the Medeans, Babylonians, Sumerians (all into the Persian Empire), with aspects of the Sassanids, Abbasids, Turks, and Ottomans thrown in for good measure.
The Greeks represent...well, Greece throughout the ages, including them being at the forefront of the Byzantine empire, sharing the Roman's Byzantine midgame tech.
The Carthaginians are a combination of the Phoenicians and later on the Caliphate(s) inhabiting that territory. (I remember the name of the Abbasid Caliphate, but not the other two.)
And of course, Rome would be. Well. Rome, but also the Byzantines, yet also the Burgundians, and also, the Kingdom of Naples.
It is probably impossibly ambitious, and I will probably never make it.
But the idea is there, and I've been putting the work in for the last few days on steps I'd take to actually make it reality.
I feel like it could work, if I did it smart, wasn't lazy, and took things one small step at a time, rather than rushing and doing it all at once, messily.
Plus, working on the mod I have been has given me the first-hand experience necessary to avoid mistakes. (Well. I wouldn't call anything I did really a mistake; if I wanted to remove something from what I made, I'd just remove it--that I keep it in is evidence that, yes, I see some charm in the aspect...even if it is something when making a new mod, I make the active and deliberate decision to decidedly not repeat. So, in that sense, they are "corrected", so sure, fit what many would call as mistakes. I'd prefer the term 'quirk'.)
Well, avoid the ones I made, anyway.
There are plenty more I haven't made...yet!
Will I follow through, probably no. I'll work on it when I work on it; when I don't work on it, I don't work on it.
I could go a day without working on it. Or a week. Or a month. Or a year.
I could permanently abandon the idea, not because of any reason, but simply due to shifting my interests elsewhere.
So who knows.
But it's something I am actively thinking about.
At least right now.