Concerning the question about why Genesis refers to Jehovah's providing a sword when humans had not yet invented such, the following Watchtower quote was provided as if it answers the question:
******Watchtower quote*******************************************************
Consider another example from the early chapters of Genesis. After Adam and Eve sinned and were expelled from the garden, Jehovah prevented them from returning. How? Genesis 3:24 says: “He drove the man out and posted at the east of the garden of Eden the cherubs and the flaming blade of a sword that was turning itself continually to guard the way to the tree of life.” Notice, “the flaming blade of a sword.” Did God invent swords?
We need not conclude that our loving Creator was the first one to make what we know as swords. Adam and Eve saw turning in front of the angels something that was blazing. What exactly was it? By the time Moses wrote the book of Genesis, swords were well-known and used in warfare. (Genesis 31:26; 34:26; 48:22; Exodus 5:21; 17:13) So Moses’ words “the flaming blade of a sword” enabled his readers to visualize to a degree what existed at the entrance of Eden. The information known in Moses’ day contributed to the understanding of such matters. And the language Moses employed must have been accurate, for Jehovah had it included in the Bible.—2 Timothy 3:16.
******end of quote*******************************************************
I had that same question a long time ago, and I remember the Watchtower article which DID NOT answer the question.
The Watchtower answer is illogical. The wording in the Bible does not allow for the answer the Watchtower gives. If the Watchtower's reasoning is correct, then Moses should have written to his audience (which was familiar with swords) something like "he posted something that looked like a sword", not "he posted a sword." He couldn't have posted a sword; swords didn't exist.
What if I were teaching history to a 7th grade class, and I were describing a warship from the 1700s which lobbed a burning ball onto the deck of another ship. Suppose that ball was about the size of a basketball, and I told the class "The ship lobbed a burning basketball onto the deck of the other ship." That would be black and white wrong. Any students with decent sense would be asking, or at least thinking, "but, there were no such things as basketballs back then. "I could have rightly said "The ship lobbed a burning ball that looked about like a basketball onto to the deck of the other ship," but I could not have rightly said "It lobbed a basketball." Basketballs didn't exist then.
Words matter. The Watchtower is wrong - 100% wrong. No shades of gray.