The reason there is only is because i live in europe and i am the only person hosting an event
i dont think there is more to it
about other mods there are roman mods out there but Rome covered a vast timespan, i believe this is the only mod about the last civil war of the republic.
Anyway, if you are looking for more roman age multiplayer you should check the taleworlds fora, rome at war is a good choice if you like earlier republic era
or the march of war for mid imperial era