Intriguing battle, thanks as usual. On first inspection, the Tyranids seem to be at a significant disadvantage with only 11 activations against 15. This is compounded by having 2 formations off-table, formations intermingled and several double activations. But the larger 'Nid formations are resilient and the BT were unable to capitalize on their initial successes.
However I did wonder whether you were using the Tyranids list correctly
- Brood units are ignored during assault resolutions, though it is not clear whether this occurred as the resolutions were not detailed.
- 'Nids get -2 when rallying if a synapse unit is present, so I am surprised that there were so many broken formations that failed to rally each turn.
- There seems to have been no attempt to "swarm" at all in the rally phase (to replace dead units). This can even be done for broken formations providing they are outside 30cm from enemy formations.
- With First Strike and sniper on CC 3+, I am very surprised that the Lictors lost both assaults that they initiated in turn #2. Perhaps you could explain what happened here.