I don't think he was commenting on the ideology so much as the war-fighting itself. I also wouldn't agree that it's correct to refer to it wholesale as "suicidal" because it includes suicide attacks, but that's a whole other discussion for a different subreddit.

Though Alexander the Great did pass through modern-day Iraq, that was mostly fighting the Persian empire. The enemy he fought that he would see in the Iraqi insurgency was the enemy found in the Hindu Kush mountains. After he defeated the Persian Empire in 329 BCE, it took him two more years of fighting rebels on the frontier of the old Persian Empire in what we now call Afghanistan to subdue it. While most militaries at the time were used to "conventional" (as was the case with the US at the beginning of the insurgency), the people that fought in those regions used hit and run style guerrilla tactics. Between a refusal to directly engage Alexander's troops and an advantage that light infantry had over Alexander's heavily armored Macedonians in the mountains, these peoples gave Alexander the Great frustrating problems that we could find parallels with insurgencies today.

Invisible Armies by Max Boot (2013)

I've also been told that "The Generalship of Alexander the Great" by J. F. C. Fuller is a great source for more specific info on Alexander the Great's counterinsurgencies he occasionally had to fight.