I'm not as sure about that as you are. What about Tolkien?
There are two main differences:
-Tolkien is high fantasy at its highest. BM actually tries to be low fantasy, despite some magical elements (e.g. daimons).
-The characters in BM are noblemen, which also happens to be the characters in most of Shakespeare's plays. Conan is also low fantasy, but a noble character based on Conan would be out of place in BM (as an adventurer, maybe). Macbeth, however, is perfect.
