The design of platinum-group-metal free catalysts for the oxygen reduction (ORR) is an active area of research in the renewable energy industry. Using quantum chemistry calculations to model the ORR of new non-precious metal catalysts has the potential to expedite their design, however there are still significant challenges when simulating these systems. Accurate capturing the energetics for the reaction of oxygen with transition metals - containing, particularly square-planar Metal-N-C (MNC) catalysts, is challenging. Primarily, this is due to the high multiplicities of such systems, as well as large electron correlation energies during bond formation and breaking. We benchmark the four-electron pathway across a number of small molecule and periodic MNC-catalysts using varying levels of theory. We explore tradeoffs between system size and the computational method used. The value of ab-initio molecular dynamics in predicting reactivity and whether experimental performance can be predicted by simulation in meaningful ways will also be discussed.