Indeed.
My counterpoint is that, in his latest material when he was trying to make the Silm more grounded and realistic, Tolkien explicitly noted that he needed to make Melkor /more/ powerful than he was already shown as being. He didn't want to bring things down to a more primitive state - he wanted to increase the already high power levels of his characters. (The essay is clear that this isn't a weakening of everyone else, either, but definitely a strengthening of Melkor.)
hS