It attacks His Lordship. The Sunday School material itself normally contains quotes from a few different versions. So here too everyone is scrambling to see if their version agrees and how to make an application. It breeds havoc in Sunday School. Thus Satan's engineers have succeeded in causing bible studies to stop dead in their tracks while everyone tries to understand and figure out what the other person's translation says.
Time runs out and next week the same scenario occurs again.
Many times when a person begins to do home Bible Study, they may take a course or just buy a study guide in a Christian bookstore. The problem is they use the King James Version. Now they have to compare quotes and try to get understanding between the 2 versions and the commentators comment. With every new version, something is omitted, added, or changed. This makes it look like God did not know what He was talking about since we have no idea which one of those versions is God's Word.