> they didn't solve the physics problems created by the engine position
The engine position, in itself, isn't terribly unusual; the 757 and 767 both have engines in similar forward positions on the wings and have a similar pitch up moment due to the engines at high angles of attack. So do a number of Airbus models. Designing flight controls to deal with this issue is not new and has been well tested.
The particular issue with the 737 MAX was that Boeing wanted to change the engine position on an existing aircraft, without requiring a new type certification and pilot retraining. That meant that the flight controls had to not just properly account for the engine position, but to do so while keeping the same stick force curve vs. angle of attack as existing 737 models. That is what drove the MCAS software system that caused all the trouble. If the plane had been designed as a new type from the start, the engine position would not have been an issue; and the redesign is basically doing what a new type design would have done, as far as I can tell from the documents the FAA has published.
> Because the engineers would not have positioned the engines there in the first place.
That would have been one possible approach, yes, but it would have involved other changes, the main one being longer landing gear and a higher ground clearance.
My point is that even having the engines in a similar position to the existing one would not have posed a problem if the plane had been a new type. Other planes in service have engines in a similar position. What caused the problem was having the engines in that position and having to match the stick force curve of the existing 737 in order to keep the same type rating.
The engine position, in itself, isn't terribly unusual; the 757 and 767 both have engines in similar forward positions on the wings and have a similar pitch up moment due to the engines at high angles of attack. So do a number of Airbus models. Designing flight controls to deal with this issue is not new and has been well tested.
The particular issue with the 737 MAX was that Boeing wanted to change the engine position on an existing aircraft, without requiring a new type certification and pilot retraining. That meant that the flight controls had to not just properly account for the engine position, but to do so while keeping the same stick force curve vs. angle of attack as existing 737 models. That is what drove the MCAS software system that caused all the trouble. If the plane had been designed as a new type from the start, the engine position would not have been an issue; and the redesign is basically doing what a new type design would have done, as far as I can tell from the documents the FAA has published.