Suggestions by @ryusoulgeed

Adelaide Kane

as Wonder Woman in Justice League

Score: +1

Tyler Hoechlin

as Superman in Justice League

Score: +1

Paul McGann

as Alan Rickman in Actor played by other actors

Score: +1

Iwan Rheon

as Victor Zsaz in The Perfect Batman Film Cast

Score: -1

Yara Shahidi

as Batgirl in The Perfect Batman Film Cast

Score: -8

Bill Hader

as Captain Cold in DC's The Flash (2019)

Score: +1

Antony Starr

as Reverse Flash in DC's The Flash (2019)

Score: +3

Angourie Rice

as Bubbles in Power Puff Girls

Score: +2

Isabella Gómez

as Buttercup in Power Puff Girls

Score: +1

Abigail Cowen

as Blossom in Power Puff Girls

Score: +3

Michael Rosenbaum

as Johnny Quick in Speedsters

Score: +1

Matthew McConaughey

as Hunter Zoloman in Speedsters

Score: +1

Iain Armitage

as Bart Allen in Speedsters

Score: -1

Bruce Greenwood

as Jay Garrick in Speedsters

Score: +1

Antony Starr

as Eobard Thawne in Speedsters

Score: +4