Indeed, "resource switching" as it is called can include whatever a consumer can consume!

Another analogy that comes to mind is from the field of ecology and is called the "Diversity-Stability Hypothesis." It posits that ecosystems (or food webs) with many species tend to have fewer wild swings in population size because a diversified resource base allows switching to prevent any one "prey" item from being over exploited. Species poor ecosystems, by contrast, would be characterized by the fluctuations of the Lotka Voltera model.

What this means in practical terms is "Don't put all your eggs in one basket." There are obvious parallels with energy portfolios, but this is really a general strategy. So when economists preach the notion of specialization, sure it can improve efficiency, but that always comes a cost that may not be known until it is too late and the formerly diversified economy is gone. I think of this most often in the terms of the U.S. food system. Where I live gone are the facilities for potatoes, grains, meat processing and dairy, for example. But we plenty of vineyards and wineries! Oh, and another crop-based economic sector is even larger but I'll not talk about that.