Defend your front cities sufficiently. Then, march any other amries you have around the east and north of the black sea to get some of those Scythian cities. After that, you will be face with Dacia and Thrace. These are never that strong, so use them as a buffer against the Brutii or possible wondering Julii forces in Illyria. These northern provinces should get you the income to assault the Selucids and Egyptians in the south.