It's 17% and 28%, but much, much higher for the most commonly used characters, which is where the divergence between simplified and traditional grows even more.
>This divergence is not the biggest deal, but still big enough to refute the claim that Japanese is easier to learn because it's "non-simplified" (there may be other valid reasons though).
I didn't make that claim. Maybe your talking about another thread?
It's not that it's easier to learn, it's that the path of going Japanese -> Korean -> Chinese is the easier, most logical path. The diverging simplified Chinese standard characters being a large reason behind that.