Basic english is about 2000 words. So a small scale LLM that would be capable of reasoning in basic english, and transforming a problem in normal english to basic english by automatically including the relevant word/phrase definitions from a dictionary, could easily beat a large LLM (by being more consistent).
I think this is where all reasoning problems of LLMs will end up. We will use LM to transform problem in informal english (human language) into a formal logical language (possibly fuzzy and modal), from that possibly into an even simpler logic, then we will solve the problem in the logical domain using traditional reasoning approaches, and convert the answer back to informal english. That way, you won't need to run a large model during the reasoning. Larger models will be only useful as a fuzzy K-V stores (attention mechanism) to help drive heuristics during reasoning search.
I suspect the biggest obstacle to AGI is philosophical, we don't really have a good grasp/formalization of human/fuzzy/modal epistemology. Even if you look at formalization of mathematics, it's mostly about proofs, but we lack understanding what is e.g. an interesting mathematical problem, or how to even express in formal logic that something is a problem, or that experiments suggest something, that one model has an advantage over the other in this respect, that there is a certain cost associated with testing a hypothesis etc. Once we figure out what we actually want in epistemology, I am sure the algorithm required will be greatly reduced.