Suggestions by @liesopdebeeck

Saoirse Ronan

as Madam Pomfrey in All the Young Dudes

Score: +2

Ashley Greene

as Madam Hooch in All the Young Dudes

Score: +1

Maggie Smith

as Professor McGonagall in All the Young Dudes

Score: +1

Michelle Fairley

as Professor McGonagall in All the Young Dudes

Score: +1

Cameron Monaghan

as Amycus Carrow in All the Young Dudes

Score: +1

Sadie Soverall

as Alecto Carrow in All the Young Dudes

Score: +2

Aubrey Joseph

as Bruce Mulciber in All the Young Dudes

Score: +1

Sarah Gadon

as Narcissa Black in All the Young Dudes

Score: +1

Keira Knightley

as Andromeda Black in All the Young Dudes

Score: +1

Katie McGrath

as Bellatrix Black in All the Young Dudes

Score: +1

Jim Sturgess

as Fank Longbottom in All the Young Dudes

Score: +1

Dane DeHaan

as Peter Pettigrew in All the Young Dudes

Score: +1

Aaron Taylor-Johnson

as James Potter in All the Young Dudes

Score: +1

Louis Garrel

as Severus Snape in All the Young Dudes

Score: +1

Sophie Skelton

as Lily Evans in All the Young Dudes

Score: +1

Ben Barnes

as Sirius Black in All the Young Dudes

Score: +1

Andrew Garfield

as Remus Lupin in All the Young Dudes

Score: +1

Michael Gambon

as Albus Dumbledore in All the Young Dudes

Score: +1

Sarah Jessica Parker

as Madam Matron in All the Young Dudes

Score: +3

Ross Lynch

as Hud in Malibu Rising

Score: -2