No way I could have made it through the years as an Oriole fan if I took this stuff that seriously.
The serious ones quit watching when the team sucks.
They do throw harder, but they've also changed how velocity is measured so they don't throw that much harder. It's also easier to go max velocity when you know you are going to get pulled after 6 instead of after 8.
Mussina led the league in rWAR in 2001 and put up a 8.2 rWAR in 1992. Do you think Eck was actually a better pitcher than he was in '92?
You could make an argument that he was the best pitcher in the league in '92, in both leagues honestly.
https://www.baseball-reference.com/awards/awards_1992.shtml#all_AL_CYA_voting
Might not be much of a difference, just a tight grouping of players.
You get that a lot in these lists.
Now if you are talking #1 and #34, that's a big difference.