I have a number of people who appear in the my.scouting report (council merit badge counselor listing), but not in scoutbook (mbc-details.csv). I also have a similar number that appear in scoutbook but not the my.scouting report.
They (mostly) appear to be the same people, just with different BSA IDs.
my.scouting ID, SB BSAMemberID
14098835, 130437387
108942362, 116581860
14194321, 109173327
12431496, 134364571
110200686, 135342478
14698185, 135320167
14080144, 12274259
132598211, 12170940
This BSA ID appears in scoutbook but not in my.scouting:
14232566
These BSA IDs appear in my.scouting but not in scoutbook
137265668
13012072