The Arione sits you at least a cm further back than any other saddle I know. He's pushing the seat forward to compensate. Probably has short femur as well.

But yes, length of femur has a lot to do with it. I ride a 72 deg STA and can just get my saddle where it feels best. Knee is a couple of mm behind pedal spindle. Could never get there with a 73 deg STA.

Old school frames, I believe, had slacker STA and longer chainstays. Modern trend is steeper STA and short chainstays. Giant advanced M/L is one of the few bikes that had 72 STA, also had a well designed seatpost where you could reverse the clamps for more or less setback. They may have steepened STA this year though.