"And now, if there are faults they are the mistakes of men; wherefore, condemn not the things of God, that ye may be found spotless at the judgment-seat of Christ." (Title page of The Book of Mormon)
This would be a great "Get out of jail free card" for the ancient writers of The Book of Mormon if the faults and mistakes in their writings were not the same faults and mistakes of the translators of the King James Bible.
The Book of Mormon repeats verbatim the mistranslated words, it often keeps the non-textual words and phrases added by KJT translators, it promotes misunderstandings of the Bible popular in Joseph Smith's time, and it doesn't even align with the "inspired" corrections of the JST.
To suggest that the Lehite prophets possessed the KJT is absurd. To suggest that God filled Joseph's illuminated translating mind with the texts he was already familiar with instead of giving him the actual translation of the gold plates defeats the purpose of bringing out new and improved scripture.
We need to think about this a little bit. If a student turns in homework with the same mistakes as another student, what is the teacher to think? If Thomas Monson came out tomorrow with a new book of freshly translated ancient scripture from Australia and a large part of it quoted verbatim sections from the Doctrine & Covenants and, say, the Book of Enoch, how would we feel about that?