are you playing on vh vh? i havent had any problems with the sauromatae.

the selucids are troubelsome though, i initially alled with every place i could send diplomats to and set about taking the nearby rebel states. then the selucids declared war on me and i have never attempted to make peace.
they have been my only enemy thus far. i have managed to take nearlly all turkey minus a makedonian and ptolmy province. and i have nearrly taken the selucids persian provinces.
money can be tight, but as previoulsy suggested you have to be patient and concentrate on mine development.