News items around the recent aviation accidents involving Boing 737 MAX 8 aircraft suggest, that bigger engine diameter demanded for a different (longer) nacelle strut for proper ground clearance which in the end had a negative effect on flight characteristics, necessitating an additional control system MCAS. This reasoning may be correct but it is not self evident IMHO.
One would think that a different engine mount point primarily shifts center of gravity, which can be statically counteracted by shifting other masses. The attack point of thrust, which also generates angular momentum if not coincident with the center of aerodynamic drag, should not be significantly affected by this geometry change.
So how does this geometry change adversely affect margins of inherent static stability and impede return from increased angle of attack to equilibrium?