They do. The Satar believe that the wars of the earth are reflected in the wars of heaven, so when two peoples go to war, their gods are fighting also.
So, Krato's gods, the Trilui gods, etc, are all real. The religious justification for the Satar to fight is that if they are defeated, their god could diminish and eventually die. And if they win, Taleldil will reign supreme over the heavens.
Our interpetation (that is the Iralliams view) is that your all Istrian path walking Niamdes...