The intent of the Great Planes PT-series of models is to be a series of Primary Trainers.

They were initially designed to be super stable with a strong self-correcting tendency. To correct a bank when you let go of the controls, you need the dihedral. To correct a nose-down attitude, you need the positive incidence in the wing relative to the horizontal stabilizer. The PT-series achieved those design goals.

If you build the Trainer wing, the ailerons won't be that effective. You may as well just make it a rudder-elevator-motor airplane. It flies very nicely that way.

Again, please realize that the PTs are for absolute novices. They weren't originally intended to be for experienced fliers...at least as they were designed.

They don't have "too much" dihedral...at least not for their intended purposes.