What is the author's tone in Sharpe's Christmas by Bernard Cornwell?

There is an uncharacteristically calming tone, of Christmas, which the author juxtaposes with the belligerent Sharpe. Since both of these stories were written for the Christmas editions of a London newspaper, Christmas is a major theme in each story. In his Introduction, Cornwell explains that he tried to write two tales acknowledging the Christmas spirit without ignoring Sharpe's belligerent nature.