Having enquired about the possibility of changing factions mid-game and reading the guide by Hax:

https://forums.totalwar.org/vb/showt...e-to-Civil-War

I tried it out in my current campaign. As Roma 244 BC I had conquered Italy and all of Greece, the Hellenes in the south had been extinguished a few seasons ago, leaving Epiros clinging on in the North and Byzantion. Also spreading West, I had finally captured Massila and was poised to launch into more of Gaul. No war with Carthage yet, but things looking comfortable in the Rome.

Then I used the script change to alter the faction - as (Thrace) Epiros and......Wow! It works!

At first I coudn't get the build or recruit feature to work, but a bit of clicking around and it was available. Deleted a load of 'froth' units (mostly spammed skirmishers) and injected a bit of much needed cash using add_money cheat. Captured Serdike and now have 3 cities, losing 2000 a season, but nothing outrageous. Sent a spy down into Greece (it was still partly orange) but once there I took a look at all the Roman units and characters I know so well! It's all still there as I left the Roman campaign, although the AI has moved them around a bit and is building ships.

A healthy influx of new adoptions and marriages has increased my character pool, the Romans asked for truce and suddenly it's rosy in the Epirote garden. It will be wonderful to 1) Survive and 2) consolidate before 3) reconquering Greece and expelling the Romans and sacking Rome, although this is far from certain as I know just how many armies I had pumped into the region and how healthy their building rosta is. They also have loads of spare cash and I have little room to manoever.

Of course this opens all kinds of new and exciting opportunities in future games.

I've already thought of choosing 2 factions in 272BC, say Rome and Carthage and have them battle to the death, alternating every few years. Imagine the damaging raids, the destruction of vital recruitment buildings, the desperate sieges and battles as time runs out, leaving the current faction in as healthy a state as possible before I take the reigns of opposing force and try and stamp out the enemy. The AI becomes less important as essentially I will be fighting against myself, sensible defence forces, intelligent building types, spare cash for mercenaries. Naturally the AI will still fight clumsily at times, but any mistake could be critical.

This the ultimate! Brilliant! I throughly recommend it for a fresh challenge!!!