Really? I've always thought of Wiggins as a good defender, athletic, quick, long, committed. Also he's improving and we're projecting this for next year.
He's got the tools and is improving, but as of last year he was below average(68th of 93 SGs by ESPN DRPM). I think projecting anything past above average is a stretch for next season.
And yeah, RPM isn't perfect, but I think it's pretty accurate here, he makes a lot of young player mistakes on that end, but can kind of make up for them with his athleticism.