Where do you get this idea? If there is no difference between good and perfect in God's eyes, then what about when He calls something "very good"? Doesn't that make it closer to perfect than good? I am not understanding this. I think a good effort is one that's on the whole good, but can contain bad elements. Maybe I am misunderstanding you?
Is the argument that Eden before the Fall of Man was perfect, and so there could be no death of animals or man there? But this isn't what the Bible says, is it? I think we have a good earth now, and yet people die ... Maybe basing our concept on what God deems "good" is where we're straying, because none of us can know exactly what His standard is. I could say the earth was good, even with the whole circle of life. But what would God say was good? How can we know?
Even something that seems dreadful to us, we end up calling "good," like "Good Friday." It was really a bad Friday! Yet it resulted in greater good ... so -- I don't think we can say there was no death before the Fall just because god said Eden was good. Maybe He meant it was good as the launchpoint for the ultimate battle of good vs. evil which He intended from the foundation of the world?