To continue,

why would the Gog Magog Alliance consist of Orthodox Christian nations of Ethiopia and Russia?

Simple, When Damascus is destroyed, Not to forget, Damascus is the seat of the eastern catholics and many orthodox ancient christian churches.

When the Muslims die  in Damascus, Sudan, Egypt, Libya, Iran are going to boil over it and come to take revenge, When  Orthodox Christians and Eastern catholics die in Damascus , Russia and Ethiopia are going to fume and get the excuse to punish Israel.

In the end, God kills this combined alliance of Muslims and Orthodox Christians in the GOG MAGOG WAR.