Even on your first play through, ratchet up the difficulty to legendary on all dimensions (campaign, battle, politics).
A nice change of place in an attractive place. It's like WW2 GIs taking their rest in beautiful Paris. ToB is like R&R from the horrors of Attila. I didn't like it on launch, played 2800 hours of WRE and ERE on Attila, then had a blast this year when I went back to ToB and played almost all the factions. It is very fair and so possibly the easiest Total War game (you are a human with the brain, you will stomp an AI on a fair fight).
It is so far from WRE on Attila, it is almost like the anti-Attila.