Fortunately or unfortunately, electronics have made things easier in this regard.
For example, Horizon offers a P-51 with a gas motor that because of the receiver/gyro can be quite successfully flown by a beginner with the aid of an instructor. So while it's a good rule of thumb, there are sportier models that can be flown with the help of an instructor that won't be outgrown as quickly as the typical high wing box trainer.
http://www.modelaviation.com/node/1111