For a true comparison the engines that were mentioned will have to be classified, for example
cast crankcase vs machined crankcase
cantilever crank vs fully supported crankshaft
And that is just to mention a few things not including fuel, oil and ratio of mix. Time on the engines or new out of the box. and of course the props.
But the final straw would be a true dyno test under controlled conditions.
Good luck to whoever has the time and $$$$$$$$ to do it.