I've been playing the scenario as Sulla, and here are some observations from it:
-Very early the Pontics made a landing in Sicily and somehow captured Syracuse which has a lvl 4 fort. They could really have used the troops against me in Macedonia and Greece. They kept the city for multiple years, and I guess this also occupied lots of Marian troops.
-At some point the Pontics also landed one land unit in Egypt, in the province Naucratis. Seems really random, and for some reason there was no reaction from the Lagids.
-Both the Pontic and Marian AI is constantly spending on all sorts of province improvements, clearing, roads, urban development etc. Is this really useful for them?
-For a long time (~2 years) the Pontics kept sending troops in ships to the sea area adjacent to Rhodos, but they never landed. When they finally did, they just went out of supply pretty fast and after that were easy pickings for my garrison. I guess sieging a huge island fortress is too demanding for the AI.
-The Marians really took their time in taking Rome, it wasn't until August 86 'till I lost it. Shouldn't it be a priority for them?