[Shun's not entirely sure where soulless shinki fall on that front, but he does know that he's never heard any soulless speak in vessel form, and he's not sure these shinki are experienced enough with it to cast without the intonation.]

I've never seen them cast one without the spell, so I'd go on the assumption that they can't for now. If it turns out wrong, then that's just better for us.

[With the plan laid out, though, Shun moves along his branch to find a slightly better position for the potential drop onto the deer ayakashi.]