I'll leave the Roman history alone since idk the first thing about it. But I want to push back on the broad definition of fascism. Fascism isn't just whenever there's violent power. It's a specific ideology that emerged after WWI in Europe. It's a hypernationalist rejection of the status quo. It distills the will of the people into one visionary leader and removes traditional limits on his power to bring the nation forward. Imposing modern terminology on ancient societies is just trying to create some grand narrative of history that happens to be climaxing.