As per the article's discussion towards the end, one should consider their areas of operations in selecting "truck" gun(s).
The only thing at the end was a mention about 4-legged threats. I would point out that, unless you live in Alaska or griz country in the N. Rockies, large animal threats can be handled 99.99% of the time (they will mostly be a dog threat) with those firearms adequate for shorter-range urban/suburban threats, and the risk of a non-dog threat is pretty low, IMO.
My .02