[burfog]

They sure could make an MCAS-free 797 low to the ground with those engines. There are lots of ways.

The popular way is with a T-tail and podded engines off the sides of the rear of the body. Boeing has produced such an aircraft. https://en.wikipedia.org/wiki/Boeing_717

Another way is with a high-mounted wing. This is popular for military cargo jets, such as the C-5 and C-17.

Putting engines above the wing is an option. Boeing did it for the YC-14, Antonov did it for the An-72, VFW-Fokker did it for the 614, and Honda did it for the Hondajet.

The landing gear could have be made to stick out extra long for the takeoff and landing, but then partially retract for passenger boarding. During passenger boarding, the aircraft could even sit on the engines.