Yeah, thanks to a good military production, research and civics strategy combined, we had only 4 accidental losses. This war strategy also removes any doubt that was shed on my proposal to go all infantry and forget cavalry, and this holds true for other issues as well.
The combination of researching Rifle, keeping Vassalage and building only macemen (city raider promoted) and going for 4 cities at once assured this win. I think we can safely change civics next session (leaving vassalage and serfdom), and conquest the remainder of Rome asap.