Suggestions by @charismagicka

Colin O'Donoghue

as Lucius Malfoy in The Marauders

Score: -19

Ginnifer Goodwin

as Alice Longbottom in The Marauders

Score: -21

Josh Dallas

as Frank Longbottom in The Marauders

Score: -9

Jason Sudeikis

as Eomer in Middle Earth: The Comedy Universe

Score: +2

Aubrey Plaza

as Arwen in Middle Earth: The Comedy Universe

Score: +1

Maya Rudolph

as Galadriel in Middle Earth: The Comedy Universe

Score: +1

Fred Armisen

as Elrond in Middle Earth: The Comedy Universe

Score: +2

Nick Kroll

as Frodo Baggins in Middle Earth: The Comedy Universe

Score: +2

Jason Mantzoukas

as Aragorn in Middle Earth: The Comedy Universe

Score: +2

Jeff Daniels

as Gandalf in Middle Earth: The Comedy Universe

Score: +3

Bill Hader

as Meriadoc Brandybuck in Middle Earth: The Comedy Universe

Score: +2

Andy Samberg

as Peregrin Took in Middle Earth: The Comedy Universe

Score: +2

John Mulaney

as Legolas in Middle Earth: The Comedy Universe

Score: +2

Tom Hiddleston

as Bertram Wooster in Thank You, Jeeves

Score: +2

Caitríona Balfe

as Mrs. Grant in Mansfield Park

Score: +2

Sean Bean

as Mr. Bennet in Pride and Prejudice

Score: +4

Stephen Fry

as Dr. Grant in Mansfield Park

Score: +2

Lucas Till

as William Price in Mansfield Park

Score: +2

Douggie McMeekin

as Mr. Rushworth in Mansfield Park

Score: +2

Eloise Smyth

as Julia Bertram in Mansfield Park

Score: +4