I posted earlier, suggesting a three-family alternative that involved replacing the Julii/Scipii/Brutii with Etruscans/Samnites/Romans - and opening the game with the Civil War already underway. The big issue was, is this even possible? And I'm happy to report that the answer is a tentative "Yes". Here's the thread where the theory was discussed and tested:

https://forums.totalwar.org/vb/showthread.php?t=45612

(For what it's worth, I feel some obligation not to just throw out wild ideas, but to perform a bit of due diligence as well)