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Erroneous options are listed at Hive Fleet army list > Tyranid war engines > Tyranid Bio-Titan Brood: Under Synapse creatures, remove the Hive Tyrant and Tyranid Warrior Brood options, which are not in the source material.

I must’ve copied another detachment list to use as a template (they were fiddly to set up) and then forgotten to delete these entries.

Thanks to Ian Wood for bringing this to my attention.