It is relevant to any mid or any forward or any combination of both, and yes it's a combination of the two. In this sense it applies to everybody, as defenders are not measured by stats. The extra disposals are more than cancelled out by the extra goals, or vice vice versa. Combination.
Nah. Only really relevant to fwd/mids. Of course, you can apply it to anyone, but the relevancy doesn't scale.
In bold is randomly applied subjective waffle. How many extra goals are are needed exactly to cancel out extra disposals and vice versa? Show me a table of weighting so at least your personal subjective take on the values attached to each statistic, rightly or wrongly, can be quantified.
In his prime Matthews was listed as a rover in Grand Final teams, Harris was listed as a forward pocket.
Yes. It's already been established that you filter out numerous reputable sources of info about Harris' career in favour of just one or two team sheets from a 196 game career ... as the meme goes THAT IS THE JOKE!
Beyond your mental filters however, there is a wealth of sources that confirm to impartial observers that Harris was a rover and that he averaged more goals per game across his career than Matthews. This is just a fact.