Bistan is one of the harder characters to farm from Fleet shipments- he only has a 1 in 3 chance for shards appearing in the 2nd column, fourth row down on fleet shipments. This is the only slot where his shards will ever appear. Other characters like Sun fac appear much more frequently because the script to generate their shards allows them to appear in multiple slots (Sun fac can appear in 4 different slots in fleet shipments, Geo Spy has chances in 2 slots, ect. There's a complete copy of the shard generation probabilities somewhere on the reddit.
Edit Found it:
https://docs.google.com/spreadsheets/d/e/2PACX-1vThja6uvkBzIpWLWNLOSNDjtGGqY8GKY3i-CHigYBH6WrfH2C4cv1saBgdIg6YcLefHVP7XafgpU6tf/pubhtml#
