A simile is a figure of speech which expresses the resemblance of one thing to another in a different category (e.g. as completely fuckwit stupid as . . . [insert troll of choice]). Butterflies and wheels are not comparable, in the same way as sledgehammers and nuts are not. That's the point. Therefore, Who breaks a butterfly on a wheel? is not a simile. Cherry pick what they can steal, however, describes what's going on quite graphically.