They can be heavily dependent on ST's. I am writing a Ph.D. thesis wherein I will argue that ST needs to have a much more prominent place in exegesis than it has had since the Enlightenment. However, the Bible itself gives us its own hermeneutics in John 5 and Luke 24, not to mention the apostolic hermeneutic. That being said, we are inevitably influenced by human ST one way or the other. The only question is this: will we be aware of it and acknowledge it, or will we try to hide it under the rug?