Another important aspect is the position of the cabin and baggage compartments CofG in relation to the wing. Having the engines far aft you need to position your payload more to the front making the aircraft tail heavy at low loading and nose heavy at full load. With wing mounted engines this is much more ballanced.
The Trident had the forward bulk cargo compartment (requiring asymmetrical nose gear) to give more flexibility in placing the payload.
I seem to recall the IL-62 having huge C of G problems
They call it differently
Illushin claims that a major disadvantage of the VC-10 compared to their IL-62 was the position of the landing gear too far aft of CG producing high nose gear loads and requiring a larger tail for rotation. The IL-62 uses the pogo stick when empty and is balanced perfectly when loaded. But maybe that is just a good excuse
