This paper presents a critical comparison of EROEI and Relational Analysis applied to the Mexican Oil and Gas sector. Energy return on energy investment (EROEI) is used in this paper as an example to flag the problem that arises when data are aggregated into a simple ratio, leading to the loss of a significant amount of meaningful information. In contrast to that approach, this paper shows how Relational Analysis is helpful for policy discussion and for embracing complexity by means of adopting a variety of categories of accounting across different levels and dimensions, characterizing the relationships among the different metabolic patterns of the different components, and integrating inequivalent views of the same system: a structural (bottom-up) and a functional (top-down).