One factor.
Turbine engines are most efficient when run at design (max continuous?) power.
So an engine that is powerful enough at altitude, will be inefficient at lower altitudes and power settings.
Probably similar with blades (big ones on top, and the tail feathers.)
IE the design that works well in thin air, might be high drag for the lift they generate in dense air.
As usual, “compromise” is the name of the game.
Does that help?