I don't specify for Sinclair because I really have no idea for him!

Sinclair is tricky because his daemon should look inexplicably close to a Minbari soul creature (while still a recognizable animal of Earth), except then everyone would comment on it.

Garibaldi is probably some kind of canid or large mustelid.

Giant otter? Unlike in many mustelid species, the males are aggressively protective of their family groups.