Obviously its either 4 thieves or 4 black mages... I think we can all assume when upgraded 4 ninjas >>> 4 black wizards, because they get much better defense and attack, and still have fast etc... 4 black wizards would be "glass canons" as they would kill everything really fast but die even faster, and with NO ability to cure... yeah
So I came to the conclusion that 4 Blackmages/wizards is the worse party in the game... anyone agrees?