Co-authors are ranked by their own lifetime peer-reviewed citation count, not by the number of joint papers with Nelson Marín Latorre Arias. A frequent collaborator with modest citation impact may rank below a highly cited collaborator with fewer shared publications.
What do A pos and C pos mean?
The # column is the rank of each listed entry for Nelson Marín Latorre Arias — rank 1 means this entry is where Nelson Marín Latorre Arias has the most articles or citations. A pos and C pos show the reciprocal: the position of Nelson Marín Latorre Arias within that entry's own ranked list, by articles and citations respectively. A low value means Nelson Marín Latorre Arias is among the most prominent contributors for that entry.