He's another variation to try.
Unit costs increased by around 15%
Unit lethality increased by 15%
Small change to morale - generally one point less
Unzip the files into your RS2 installation. This will overwrite the export_descr_units.txt files in the following places:
/data
/data/_IMPORTANT_STUFF/Single_Player
/Play_Parthia/data
/Play_Sarmatia/data
/Play_Scythia/data
so I advise you to make a backup copy of the export_descr_units files in these locations.
Again, comments on how these changes feel would be helpful.