MK never wanted to share any credits
This sounds a bit misleading to me. I think every musician will bring in his own parts automatically. Rock music is not composed like an opera - this is the transcription for your part, please play it - but starts with a rough idea of the song (chords, lyrics, melody) and the rest develops. Including everybody's name in the composer credits will cause nothing but problems with the publishing side of the business and does not make sense for this reason.
In the case of TR and Alan, we know that Mark and Alan worked together on the song, I think it is even mentioned in the Oldfield book. Possibly even complete parts or blocks - I can imagine that e.g. parts from the 'camera' section after 'three lanes moving slow' - might be based on Alan's input, but the 'song' (in the sense I described before) is Mark's composition alone.
Ingo, the credits thing demonstrates what kind of band one is...
If you take a look to any Toto, or Led Zeppelin record, if the bass player, keyboard, drummer etc added to the song any particular line, groove, whatever, they got their credit, as they were in a band, a true band. No matter who came with the lyrics, if any other member contributed to the song, they got credit.
Dire Straits was not a band like, let's say, Toto or Led Zeppelin, it doesn't matter if the drummer bones with a great groove, the keyboardist with a great oiano, Hammond line, they got no credit as they were no members of a band, they were hired guns. That's to me makes DS not a real band, just a MK vehicle.