The really simple suggestions usually leave out a whole bunch of details.

It's really simple to make the measurements online applications ask for. It's dead simple and takes almost no time to do it.

Measure the wing's tip chord, root chord, half span, and sweep.
Measure the same things for the horizontal stab.
Measure from the LE of the wing to the LE of the stab.

How hard is that?

The applications deal with wing sweep, taper, etc and consider all the things that matter for pitch stability. The real simple techniques don't.