I think John Gill's position is the best:
who are of note among the apostles;
were well known by, and in great account with the twelve apostles, though not of their number; they might be converted by them, and be followers of them in Judea; they are thought by some to be of the number of the seventy disciples, whom Christ himself sent forth to preach: Andronicus particularly is mentioned among them, and said to be bishop of Pannonia, or rather of Spain; (See Gill on 10:1); however, they might be preachers of the Gospel, and be persons of great fame and renown as such; for which reason they might be called apostles, that being a name sometimes given to ordinary ministers of the word, and to such who were messengers of the churches, ( 2 Corinthians 8:23 ) , as these might be, and were famous for their prudent, faithful, and diligent discharge of their office and duty:
From Gill's Exposition of the Bible