Speed graphs for Spitfire and Hurricane

[bw_wolverine]

I don't understand something.

Weeks and weeks ago, everyone was saying that the only aircraft that had historically accurate performance was the Spitfire IIa and that the other aircraft needed to have their performance increased as well.

Now, suddenly, because 1C has decided to reduce its performance, people are popping up saying that the Spitfire IIa was over modelled. And now that the Hurricane is being reduced, people are claiming that it has always been overmodelled as well.

What new historical research and findings appeared between those posts and these posts that has altered everyones views?