Sorry if this has been discussed before in a thread I could not find...
It seems interesting that the order of the songs will not be the same on the CD (i/o number 4 and Four Kinds of horses number 5) and digital download compared to the vinyl (4KOH is 4th, I/O 5th).
PG has been known to pay attention to the order of the songs on the albums, and especially always putting at the beginning of each side of his vinyle releases the most complex songs (which is why in the original version of SO, it is respectively Red Rain and In Your Eyes, though now In Your Eyes has been pushed back to the end where it was meant to be all along...). There is more space on the outside of a vinyl, so the sound has a better definition.
I am wondering if this is not the same phenomenon, with a preference for having Four Kinds Of Horses and its "musical worms" benefit from the added definition, compared to i/o. On the CD, he may have prefered to have two up tempo songs (The Court / i/o) and then two darker songs (4KOH / Love Can Heal..). This is just me guessing, however, so happy to hear if anybody else has any information or wants to speculate some more