Why would Evans-Pritchard be concern-trolling? I'm not saying he isn't, but I don't really know anything about him and don't see why we should prima facie accept that he is.

Regarding the evolution of the economic ideas of the Front, over time they have certainly been... dynamic.

At the end of the 1970s, Le Pen refurbished his party's appeal, by breaking away from the anticapitalist heritage of Poujadism. He instead made an unambiguous commitment to popular capitalism, and started espousing an extremely market liberal and antistatist program. Issues included lower taxes, reducing state intervention, and dissolving the bureaucracy. Some scholars have even considered that the FN's 1978 program may be regarded as "Reaganite before Reagan".[133]

The party's economic policy shifted from the 1980s to the 1990s from neoliberalism to protectionism.[138] This should be seen within the framework of a changed international environment, from a battle between the Free World and communism, to one between the nationalism and the globalization.[93] During the 1980s, Le Pen complained about the rising number of "social parasites", and called for deregulation, tax cuts, and the phasing-out of the welfare state.[138] As the party gained growing support from the economically vulnerable, it converted towards politics of social welfare and economic protectionism.[138] This was part of its shift away from its former claim of being the "social, popular and national right" to its claim of being "neither right nor left - French!"[139] Increasingly, the party's program became an uneasy amalgam of free market and welfarist policies.[93][140]

Under her leadership, Marine Le Pen has been more clear in her support for protectionism, while she has criticised globalism and capitalism for certain industries. She has been characterized as a proponent of letting the government take care of health, education, transportation, banking and energy.[136][140]

My impression, which might be wrong, is that the Front is mainly about completely other issues than economic policy, and adapts its economic policy over time in ways that the economic policy can support the main focus of the primary party policies.

Peak oil is not an energy crisis. It is a liquid fuel crisis.