Research contribution in a research article is determine by the order of the authors of the paper. For example 1st author is the one who has contributed the most, and so on ..... What sense it makes to give an importance (if it is there) to the corresponding author.
I think they are a focal person for doing the correspondence between research journals and research team and anyone from the author list can be a corresponding author. Does it justify to rate corresponding author equal to or next to the first author.