...The B737 on the other hand seems to have an elevator only marginally smaller than 1/4 of the full horizontal stabilizer including the elevator.
This must be a significant difference.
That MAY- repeat MAY be due to basic design for FBW versus ' cable ' control backup design for 737 and prior.
I note that seattle times article today mentions that initial stab movement was supposedly limited to .6 degrees for flight envelope and even for extreme csse. Flight test apparently showed/proved it needed to be 2.5 degrees for extreme conditions- due to extra lift from engine cowlings at high AOA- but somehow the documentation approved never got that number changed And/OR even thenit was not considered critical, etc
NO matter how one slices it- the ' fix' was FUBAR - and forgot that AOA sensors can easily be bent orhit by birds etc