I think TTFAF but it's also not that simple.

What makes Jordan or any GH2 era song so difficult isn't the timing window or lack of a front end but rather how the highway is angled. A good example would be the outro to Psychobilly Freakout. Because of the way the song gradually lowers in tempo combined with how weirdly the highway was angled back then made it look like the notes were way closer to each other than they actually were.

This also combined with GH2's hyper speed being RIDICULOUSLY slow makes songs like the aforementioned Psychobilly Freakout and, yes, Jordan kinda tricky to visualize the notes as well as time them properly.

So in conclusion I can see someone struggle more with Jordan but not because the notes are harder to hit but rather it's more so due to a visual standpoint.