Imagine if Mark Sanderson had been arrested and imprisoned while in Russia. I can’t help thinking the response of the other GB members to the persecution might have been different than it has been if it was Mark Sanderson languishing in jail. They might have been less likely to antagonise Russia with “king of the north” speculation, and their diplomatic efforts to secure release might have been more energetic and focussed on success rather than grandstanding.
On the other hand, maybe the GB could have lived with Mark Sanderson in jail. Maybe he was sent to Russia by the GB because he was in some sense the most expendable in case anything went wrong. Surely not, just some idle speculation.