which perk should I get?

I have a solid deathslinger build: brutal strength, dms, pain res and nurse's calling, I want to replace nurse for either coup de grace or corrupt intervention, i've heard coup the grace is good since you can get hits even when you shoot a survivor across a pallet, but I already have brutal strength to deal with pallets, and corrupt is good since deathslinger is slow and has no way of moving through the map, but after 2 minutes it's just an empty perk slot, so which should I choose? or do yall recommend another perk? I only have enough to buy a 4.500 iri shards character though