Question about invisible providence (Arc 6 phase 1) [spoiler discussion]

So I’m almost done with arc 6 phase 1 and I recently read that one chapter with the fork and ram eridna and Subaru going right getting affected by the miasma and everyone going on a killing spree (insane chapter and loop second only to rabbit death in arc 4) I’m actually confused on why Anastasia chose Subaru over rem in terms of surviability but that’s not my main question… in rams and Subarus fight Subaru used invisible providence to hold down ram as he strangled her to death and from the fight with the centaur that I’ve yet to finish the narration said that invisible providence could tear the centaur limb for limb meaning that invisible providence is pretty strong and a ton of grip strength…. So my question why doesn’t Subaru use invisible providence to strangle his opponents instead? And you know crush their throat they won’t see or know what’s hitting him as Subaru just stands there he could get rid of many opponents using this method for example batenkaitos or any other human