Exception to the rule III
Normally wing aerodynamics are main cause for placing the engines as far low and front of the wing as possible.
Placing them to far up disturbes the airflow at high AOA reducing high lift performance and making leading edge device design (i.e. slats) difficult.
Placing them to far aft affects transsonic drag by violating the area rule.
I´ve seen a diagram of some NACA report showing CL and transonic CW effects of engine position, with some typical airplanes drawn in as example. This was in the design papers of a 70 seat twinjet project that has been cancelled later on. I can´t find it on the web.