The current iteration of it doesn't really make sense to me.
I used to have an impression that the Army was a coalition of survivors from numerous worlds conquered by the Legion, but as it turned out it solely consists of Light-infused draenei. Where did these draenei even come from? According to the description of the in-game faction, they are the "draenei's finest warriors who followed Xe'ra across the cosmos". Does this mean Velen's group was not the only one rescued by the Naaru? And if so, why was one group chosen to form the Army while the other was on the run for thousands of years?