> There would be a stream of Russian soldiers going back in body bags and likely atrocities that would strengthen and broaden the sanctions.

We're already past both those points - estimates are tricky but it seems likely that over 100,000 have already been killed and the Ukranians are already excavating mass graves in retaken areas. I don't think there's much headroom to increase sanctions? What's left unsanctioned?

(by comparison, I see figures for the US lost about 60,000 KIA in Vietnam and 7,000 in Iraq, across the whole duration of those wars)