I used this deck to clear my 4th Nightmare run as Mom.
The first 2 cards generates money so you can buy medkits.
No cards to buff heal efficiency, so most of the time you'll stay behind and wait for your teammates to be incapacited before healing with your medkits so you can restore the lost extra life and trauma thanks to the 'Medical Pro.' card.
Less heals to keep your teammates full health means that you have to help offensively.
If you want to clear common ridden => LMG
If you want to help on killing mutations => Sniper.
(I always picked Barret + Tec9 if I had the choice)
+ Generates money, even if you fail the map challenge
+ You won't heal a lot but you can restore trauma and extra lives pretty fast
+ Defense / Offense flexibility, capable of surviving on its own
+ Use speed & move speed to be able to solo clear objectives (Hell's Bells, Broken Bird...)
- No buff for heal efficiency so pills and bandages won't be that useful
- You have to carry medkits, therefore you have no panic pills
- If your team doesn't want to share money, it'll be hard to keep buying medkits, lessening the purpose of this build.
Remember that you need to stay alive ! You'll be the one reviving your teammates and healing them so they get back their extra life.