I can add 2 points?
1st is that ANY plane is a series of design compromises and 'best guesses'!

The other is that some of the airplanes contained in the OP list come in single and 2 place versions in full scale - with otherwise identical airframes (other than possible minor differences in tail moment and side area) getting different model numbers. Others variances may be due to engine size? Those factors removed for RC purposes, there really aren't THAT many different planes available.