Natural order of things, it seems to me is VIN, low to high. I'm not sure I like the engine VIN beneath the frame VIN, as it appears to makes it less easy to see the increasing order VINS, ie, confuses the natural order (yes, I realise that is why the "F" and "E" are there). E VINS alongside frame VINS seems more logical to me, but does mean another column, which maybe compromises page width?
To group info against owner name would make the list rather random, and of course there are more VINS without owners than with. Also, as has been commented, owner information tends to become incorrect as bikes change hands.
Current VIN directory does include "loose" engines / frames, valid data after all. Frames only are easy, as they fit in the natural increasing number system, but engines without frames? - who knows where they fit!
The existing VIN directory was laid out with line breaks at various places (between 2 digit and 3 digit, at each 4 digit break point after 1999, 2999, 3999, etc) to make it easier to see, given how long the list has become. This also affords an opportunity to group those loose engines say at the start of a VIN range block (1xxx engines at start or end of 1xxx frame block for example; not foolproof but sort of fits?).
Just thinking out load at this "get it right" stage, you understand.
Cheers - Chris R.