I think some folks are putting too much stock into the religious motivations of pagans of this time. Sure, some believed that glorious death in battle guaranteed a better afterlife, but I don't think this was the main basis for great deeds and warlike-spirit. Most Roman soldiers during the 2nd Punic Wars were likely fighting because they were defending their city and homes from a foreign invader (Hannibal). Persian soldiers fought at Thermopylae because they were conscripted to. As far as I know, Ahura Mazda blessed truth and justice and things like that, not reckless battlefield heroics. Carthaginians in the 3rd Punic War fought to prevent their own enslavements and slaughter. Alexander fought for everlasting fame and glory, not to gain some kind of comfortable afterlife. The men beneath him fought for riches and plunder. The Teutones fought the Romans under Marius in order to secure a new homeland (and lost badly). I think it would be cool to have some kind of tech at the temple that boosts your units, but base it on religious rites or rituals. These were very important to superstitious soldiers and helped curry the favor of the gods for their cause, or so they believed. Alexander sacrificed with his army's priests every morning. Priests from many cultures ritually slaughtered goats, chickens, and cattle prior to battle (Greek: "Sphagia") for favorable omens. Ritual feasts accompanied religious and civic festivals, with burnt offerings "given to the gods." Spoils of war were dedicated to temples in honor of the gods and to gain their favor. Religious oracles were consulted by private citizens, governments, and kings for guidance.