Who is Stan Thomas from Stern Men and what is their importance?

The taciturn father of protagonist Ruth Thomas, Stan is a successful lobsterman on Fort Niles Island, earning the nickname Greedy Number Two while Greedy Number One is his best friend and former mentor, Angus Addams. Stan's wife, Mary, abandons the family mysteriously when Ruth is four years old, to give birth to a severely mentally challenged child, whom she raises in Concord, NH.