Arknights Welfare TG-2 Clear, Challenge Mode

To the Grinning Valley level TG-2, Heat Drilling, Challenge Mode, cleared using only 6 Welfare operators.
Here again I put my operators really close to the enemy gates, mostly because the tiles on the bottom near the gate were all unavailable in this challenge mode. This allowed me to use one healer and one caster covering both gates. For my melee operators, I tried to use arts damage operators, because the Roar Knightclub Trainee and the Independent Knight Shielder are both much weaker in their resistance. See what you think....
Welfare operators are as defined at:
arknights.wiki...
wiki/Operator/Welfare.
Comments and advice are always appreciated.