Come on, man. You can't just say indeed and leave it at that. That's a hefty claim and you need to cite it.
Say you have an army of 1,000 archers using these poison arrows. They may carry something along the lines of 30 arrows each with, just for argument, 1 gram of poison each. That means the refinement of 30 kg of poison to be refined and distributed to an army. Considering the era, call me skeptical.
EDIT: Oh, and before I forget, Greek Fire, Poison Arrows & Scorpion Bombs: Biological and Chemical Warfare in the Ancient World hasn't exactly gotten glowing reviews from academics either.
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