What's your source for that? By most accounts the Lancaster was the better built; partly due to the Manchester being designed to cope with a catapult assisted take off.
THE SCIENCE OF BOMBING: OPERATIONAL RESEARCH IN BOMBER COMMAND. What basis are you using to describe ....
and not half as destructive as the whole series of Halifax that had uncontrollable rudder issues
It only affected the early MK I and II and was cured from the MK II IA onward.