For people who want to try and reform the Seleucid Empire you guys could include a small rump state. The Empire (little more than a city and a few villages) existed until roughly 69 BC or up until Pompey.
However, in 80 BC, your start date, the Seleucids were a rump state under Tigranes the Great, king of Armenia. This could be portrayed a very weak vassal or whatnot.
Anyway, it would be cool to play as them.
You could also add Kapadokia and Media Atropatene to the Faction lists. The later would also be a vassal under the Armenians. While we are on this list we cant forget Kochis, Iberia and Sophene. Some of those would just be copies of the Pontics and Armenians. Similar rosters.