Well, you changed your sentence from "God wrote the Bible" to "Bible come from the word of God".
Anyway, of course there is a conflict with anyone who says "God wrote the Bible" to "Christian scholar accepts he doesn't know who wrote Hebrews".
This is the fourth time I am mentioning this. Its kind of strange really.
Well, if christians say god wrote the bible, they aren't saying a being came down and scribbled his name. They're just saying that the authors of the bible were inspired by god and what the authors wrote (as god's reps), god wrote. So, in the christian's point of view, god actually "wrote" the bible.
I think it's more of a spiritual thing of god writing the bible and people's beliefs not a historical thing. Most christians know god didn't come down with paper and pen to write the bible. More say that the biblical authors were inspired. Just the "language" believers use determines how literal they take this. It doesn't change the theology nonetheless.
Whoever wrote hebrews must have been inspired by god in christian theology because spiritually, they are more concerned with the inspiration rather than the human authors.