FoE should play up the animosity/stratification between races more. The Enclave already does this for the pegasi. I'd add to that unicorns usually ending up as mercs/slavers/raider bosses since they can most easily use guns and other weapons, and thus lord it over the earth ponies.

On the other hand Steel Rangers should be mostly earth ponies, using power armor and robotics to compensate for their lack of flight and magic.