In sum, Robert H. Frank is stuck in the pre-capitalistic feudal age, where there is no such thing as mass production, and practically all goods beyond a few essentials are luxuries, accessible only to people high up in the social hierarchy.
With the coming of capitalism, things have turned 180°, and now almost no goods are permanent luxuries.
Not only love but also the market can level ranks, “and therefore…”
Even there, he would not be making much sense, because the hierarchy in those bygone days was much more stable than it is today, when mobility, both upward and downward, is the order of the day. Dukes would marry duchesses; and peasant boys, peasant girls. The caste or class one was born into was destiny. Hence, arms races were contained even under feudalism.
It may even be that the whole reason for rigid social hierarchies is to defuse arms races. But we have invented a way to channel human competitiveness into socially beneficial outlets. Frank’s exceptions to this rule are too insignificant seriously to challenge modern economic thought.
I might recommend The Darwin Economy to a medieval scholar who wanted to know the causes of famines, pestilences, and wars; but it is a mere curiosity in the modern age.