Yes, I do feel a bit sad. Silly really, as they're only a bunch of pixels. However, a couple of generations had passed since I was working closely with the village and I no longer knew them by name. With 90-odd it would have been pretty impossible, anyway.

I chose to wipe the tribe with the lowest number of collectibles, and gave them a painless death via 'Start Again'. Their name lives on in the new tribe I've just started (provided it survives).