Sadly, I don't have much hope that the new Rittenhouse will be any scarier than the old one. The format of the show will stay the same: Rittenhouse tries to change history and our heroes stop them. The "reasons" for changing history will change but that's about it.
I suspect that you're probably right. It would be neat if they switched the format up a bit if they come back next season. Perhaps Rittenhouse finally succeeds at changing history and the Time Team have to figure out how to get time back to how it should be--or closer to it.