Both posit that the ‘Flood’ was caused by the melt off of the glaciers due to a global cataclysm - Hancock, I believe, posits it was due to a comet impact(s) and Schoch posits due to solar/sun activity.
Physical and geological evidence point to comet impact, not solar activity. Hancock and dozens of scientific papers point to it, Schlock is full of it, and himself.