Looking at TSRs game and Saladin's LBs are insane. He has CG3, Drill 2 guys defending his cities, and has now added maces as well. It's going to take tons of praets/cats to take him down. Zara is also moving a stack in their direction, and they could easily be the target. I think he's cautious with them + brennus + gilgamesh, but they are the closest of the 3.
I really underestimated how difficult this one would be with the AI only set to Monarch.
I don't think any 1 aspect of the game made it very hard, but all of them work together to make it very, very difficult. Raging barbs didn't hurt the players, but it fed the AI defenders XP. Needing to build 7 wonders in Rome pushes players towards mines + farms rather than a cottage capitol for research, and also ties Rome up building wonders. The # of city limitation then makes it difficult to get that lost research elsewhere, and on top of that the unit requirement in Rome eats up gpt in unit maintenance. Compounding all of this is the no tech trading option.
All of the other side effects of no tech trading are difficult to deal with also. No selling techs for gold, no easy +relations boost with the AI, no bribing AI into war with each other, etc.