If I have a plane, and put it on my workbench with stab absolutely level, it is quite easy to roughly check all other angles, and even the horizontal stab displacement relative to the wing. If something is out of whack, I can spot it right away. The wing with 3D foils seldom has more than 1° incidence. (cambered foils have 0° or negative incidence).  Probably closer to 0° if the CG is aft enough. In the old days with marginal flight power, even cambered foils had positive incidence and were nose heavy for added stability. The extra incidence angle would also result in extra engine downpull angle.
Motor down angle in modern powered planes would be very close to 1/2 airfoil camber % in degrees.
Only then would I turn to CG issues. A plane can be quite tail heavy before it becomes non-flyable. It also can be very nose heavy and still land decently with full up elevator.