Does religion make armies stronger?

[Anomalocaris]

The Iraqi army had every technological advantage needed over ISIS.  In the end, the only thing they used were good running shoes.

Iraqi army did not give itself the technological advantage.   Technology gifted from outside often counts for much less than the wherewithal to develope the technology.   It is the wherewithal to develope the technology in a broad and sustained way that religious fervor, try as they might for their own short term expediency, can not but cripple.