Hi Simon,
For a table using the DOL lock scheme, table scans are done using an OAM scan. The OAM for the data pages contain an entry for each allocation unit that the data has extents allocated on. Each allocation unit has an allocation page which contains 32 extent records that record which object + index the extent is allocated to and a bit-map showing which of the 8 pages in the extent are currently in use (i.e. have at least one row on it). The scan uses those bitmaps to determine which pages need to be read to retrieve all the information.
If you create the table with the APL lock scheme, I think you will see the page linkages you are expecting.
Cheers,
-bret