One example to support my point that sub 10:00 is harder(Remember I am an 800 runner so I am not some kid with a 9:59 pr that is touting himself on the internet). My junior year our all state middle linebacker ran the 4x100 and 4x400 all year. We decided to throw him in the 4x800 at the end of the season, he split 2:02 in his second 800. I am sure with 2-3 weeks of 800 specific training he could have broken 2:00. He could have had 2-3 months of 3200 training and I don't think he would have sniffed a 9:59. There are countless kids like this in high school, with 50 or 51 speed in the quarer and mental toughness that have to do the 4x800 and can split sub 2:00 off of almost zero 800 training.