outta curiousity, is this a 'discuss', 'to what extent do you agree' or 'is this true', or is it something else i can't think of?
more is the main character, therefore if you don't include him at all in the essay, then there's something wrong. the other characters (ie, cromwell, rich, the king, norfolk, common man) etc are also characters that you could include in this essay but perhaps to a lesser extent.
if i was writing this i would probably agree to an extent, but try to defend sir thomas more by highlighting how corrupt society was at the time and so on and so forth by using the other characters... and examine what the 'consequences' REALLY are -- you have to remember -- more believed that he had no choice BUT to do what he did. he believed that by swearing to the oath, he was giving up his mortal soul for his immortal one and it's just something that he could not do.