The Book Mysterious Island Peoples' Name Are Mystified

I am reading Jules Vern's THE MYSTERIOUS ISLAND , the Kindle version.  There are only five characters to keep up with and none of the names are similar.  However, I get them mixed and confused.  Why?  Because Jules Vern sometimes refers to them as by their profession, which  may divide itself several names.  For instance there is one guy, probably the main protagonist,  named Captain Cyrus Harding, a Union Officer, but sometimes he is Captain, sometimes his first or last name, sometimes, his rank, sometimes his other profession, which I think is an engineer, unless there is  an engineer hiding within the 5; The Captain has a servant , a free black man named Nebuchadnezzar or "Ned" for short, he has a string of  alternative names too;  Gideon Spilett, a fearless war correspondent, aka Reporter;  Jack Pencroft is sometimes called by one of his names, or "the sailor" or sometimes the "Seaman".  Herbert Brown, other than the two names is known  in the book "the boy", "the orphan", "the youth" and "the young man".  So, there are between 12 to 18 characters which are really only 5 people.  Wait!  I forgot, there is also a dog... I haven't noticed but I think he probably has a string of possible identities also.  To keep me straight, I went to Google and searched for List of characters in Mystery Island and printed it off.  Which now, I now use as a quick reference..... and by the time I get all the various names and nicknames lined up with the right, watch the characters start giving each names.

And to add to the confusion, while googling MYSTERIOUS ISLAND  I got the hint that Captain Nemo will make his presence known.  Captain Nemo was of course the star of Jules Vern's book 20,000 LEAGUES UNDER THE SEA - Which I think the Mystery Island might be the Nautilus's home port.  I will find out soon enough, then I will be confused over which "Captain" is the subject at the moment, Nemo or Harding?