"Various elements that were unique to every individual served as a signal that the passenger could reach out to in an attempt at reconnecting with a host. DNA, electromagnetic patterns, patterns she could barely measure with instruments, all contributed, none was absolute. Once the connection was established, powers were possible as well. A moment of trauma sped the process along considerably."
To clear up the misconception of Shard connections being solely dependent on DNA. Still a major factor admittedly, but it's not the sole one.
Also wouldn't the Culture literally taking out Broadcast that's apart of the very much alive and active Zion Network effectively prompt a major response in retaliation? Considering that Zion is literally the Guardian of the Cycle, regardless of pseudo-depression about Eden, and another thing all Shard's are Zion the Enity Collectively. Which make it weird that they want to try to personify a Shard, but want to 'deal'(as in kill) with Zion, despite the two being capable of being synonymous.
Granted I still need to read the story in full, but that's what glaring issues I found with some discussion based around the story.