Obviously, the great Watchtower scholar CT Russel stole from earlier writers and mixed in some Egyptology, Occult, Pyramid measurements, and Masonic beliefs to come up with the initial timelines. Later "Scholar" Fredy Franz (who attended one year of College) built on those and was every bit as wrong. He also stole much of his work from earlier religious Bible "math whizzes" from the 1800s and 1600s.
Basing your life and others' expectations on ancient verbal histories and expecting them to be accurate is foolish.
Was there a "flood" that covered the ENTIRE earth in modern history? NO. Was there a global sea level rise at the end of the last ice age that drowned many coastal civilizations around the earth- especially in the Black Sea area? Yes. And of course, people's grandparents described this as a "global flood". https://animations.geol.ucsb.edu/2_infopgs/IP2IceAge/fBlackSeaFlood.html
Did man (Adam & Eve) appear only 7,000 years ago? Of course not. There are CITIES older than that. https://www.smithsonianmag.com/history/gobekli-tepe-the-worlds-first-temple-83613665/
We all were forced to sit through boring book studies in the 60s and 70s reciting baloney from "Dr. Strange love".. Fred Franz who perfected his theories with his adoring boy fans in the Bethel Sauna. His bright Red "Life Everlasting" book was studied every week. Watchtower can not escape the fact that so many copies are still floating around.