I can't really answer your question but do know that they will hire for a position that may not be listed.
My grandson went when they advertised, the position that he saw was in housekeeping. When he was interviewed and the person saw his training and work in culinary arts they told him they had positions on the Pride of America and started him on the hiring process. He is now working his second contract with them.
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor 2012, MSC Poesia 2012, MSC Poesia 2013, Carnival Legend 2013, MSC DIVINA 2014, MSC Divina 2014, Carnival Liberty 2015, MSC Divina 2015, Carnival Ecstasy 2015, NCL Star 2016, Carnival Glory 2016, MSC Divina 2017
Why not? I'm sure not everyone has done the type of job they were hired for. At least getting hired is getting your foot in the door so to speak. Then watch postings for upcoming opportunities. Or, as another posting said, there's likely "inside" info on jobs available or possibly potential openings.