How to review similar academic papers for a literature review?
It looks that it is an example of two independent studies that obtained similar results so you might comment that this reinforces the claim that the reported results are correct. However, most probably the studies weren't exact replications so it might be good to mention the differences between the studies.

It is also a good idea to investigate the journals they were published in - maybe the earlier paper was published in some obscure journal and the second one appeared in a high impact factor one? Have you looked at 'cited by' numbers (in Google Scholar)? Which paper got more citations? Maybe there are some publications that mention both papers? This might give you a clue how the community finds both papers and which one made more impact. It is also plausible that one paper got bigger publicity simply because of more known authors/research group.