From what I recall from reading The Zombie Survival Guide, Max Brooks's knowledge about actual combat conditions and equipment is about as extensive as Druckmann's knowledge of sex that doesnt involve watching a well endowed black gentleman crunching his wife.
Seriously, the whole "plate armour is worse than toilet paper and will just be easilly ripped off" thing is just the tip of the iceberg in terms of dumbass things he has claimed, with my personal favourite being his autistic obsession with weeb ass shaolin shovels as "THE ULTIMATE ZOMBIE KILLING WEAPON" and insistence that "assault rifles are worse useless because the original M16 in the 60s wasnt very good".