Err, Draco sounded pretty formidable to me. He came close to overcome his education, and even did overcome it to some extent. Crabbe and Goyle are very apt bruisers, formidable broomstick riders, and once showed a rather sophisticated education (being able to change the level of politeness at will without sounding fake is quite a feat at that age --"Da boss want to speak with ya" vs "Mr Malfoy requests an audience with you").

Your suggestions do sound good, though.