Like ok they get lead roles from sm privilege and being from snsd, but as actresses, lets be honest only yoona is making some noise as a film actress (and her acting is oft criticised as well but i ain't wanna sound like a hater), and if we're being generous seohyun has been in some notable projects.
but all the others like sooyoung hasn't made any major splash, yuri has literally been criticised for all her acting. some throw tiffany as an actress as well (musical actress) but she hasn't done any legit kdramas so i wouldn't put her in there.
like sones will put out some tweets like "yeah lol kdrama fans are surprised these actresses are all in one group " but cmon lol aint no one knows those flop dramas.