Because I have to put it somewhere:

KJ Charles protagonists by Hogwarts house.

Gryffindor: Stephen Day, Archie Curtis, Richard Vane, Silas Mason, Nathaniel Roy, Jonah Pastern, Simon Feximal

Ravenclaw: Dominic Frey, Rowley Green, Crispin Tredarloe, Saul Lazenby

Hufflepuff: Harry Vane, Lord Gabriel "Ash" Ashleigh, Clement Talleyfer, Ned Hall, Ben Spenser, Martin St Vincent, Robert Caldwell

Slytherin: Lord Crane, David Cyprian, Daniel da Silva, Justin Lazarus, Julius Norreys, Francis Webster, Theodore Swann, Randolph Glyde

Which means we have:

Gryffindor/Slytherin x4, Gryffindor/Ravenclaw x2, Gryffindor/Hufflepuff x2, Ravenclaw/Hufflepuff x2, Ravenclaw/Slytherin x1, Hufflepuff/Slytherin x3