Arknights Welfare TG-7 Clear, Challenge Mode

To the Grinning Valley level TG-7, Moving Mountains, Challenge Mode, cleared using only Welfare operators.
I was surprised at how simple this clear was. All I did was have a healer, a ranged melee, a sniper, and a pusher or puller operator at each side of the map. The ranged melee and sniper took care of the Infused Originium Slugs before they got too close (mostly) so that their death damage didn't impact my operators too much. The healer took care of the operators when this tactic didn't work as desired. And the pusher/puller shoved enemies into the holes.
Welfare operators are as defined at:
arknights.wiki...
wiki/Operator/Welfare.
Comments and advice are always appreciated.