The Steiner pages are naturally set up to mimic the sequential ordering of the Scott catalogue as you probably know.

So regular-semipostals-air post- postage due- etc is the usual order.
Since I use the Scott catalogue for the WW classics, I don't change the sequence.
But if one is following another catalogue- say Michel- then it might make sense to order the pages based more closely on that catalogue's presentation.
Does the Unitrade catalogue for Canada separate out BOB, or integrate the issues into the main regular section?