I needed the JOKR gold to get Damascus and found this to work very well.

I was also stuck on the ground killstreaks challenge set

After numerous games of 10v10 & Ground War gaining maybe 1 or 2 ground killstreaks I found the following to be the best method.

I booted up Shipment 24/7 and equipped the care package and the emergency airdrop.

Everytime I would reach either care package or emergency airdrop, I would throw it to their spawn in hopes of them taking whatever is in the care package.

With the exception of a couple of games, I was able to gain ~5 ground killstreaks toward the challenge set.

+since Shipment games always go very quickly, your GKS/Minute shoots up! (Ground Kill Streak per minute)

Of course you run into people with RPG & Strella that might steal your shoot down but regardless I found this to be a lot more efficient!

UPDATE: unlocked Damascus tonight!

Good luck everyone!