IKR...hard for die hard coop players to fathom but I have to admit, although Monastery was the first Crushing I got, it was a random I met that did most of the "heavy lifting".
I'm just glad I got Overseer when I did...I think it's gotten harder over time.
Pedro and I would just do the same thing over and over each time we played it to get it for someone. A couple times, the person we were helping managed to lag out before the statue part. We decided to finish the level anyway and found out we could still get it. Wish he was still around.
I think I could still pull this off with Egyptian Camel or Bunshing. But it would be the same as with anyone. We would need to have an understanding of what each other was going to do beforehand.
For Monastery (and Overseer).
Go to Youtube.
Search on "BoneSickle", "Monastery Rocket Spawns Explained (Uncharted 3 Co-Op)" and/or "Overseer Trophy Talkthru (Crushing Curator Medal)".
He has other videos and if they're half as good as his Monastery ones, they'll be excellent. The most important thing (in my view) is understanding how the RPG guys spawn.
Watch the videos thoroughly. Get some friends. Make sure everyone knows their role and practice. Even with friends who all know what they're doing, it can take several tries. You can execute your plan flawlessly and still get a bad break so be patient and persevere.
Don't be afraid to tinker with BoneSickle's strategy. For instance, rather than trying to block that one spawn point (for RPG position 4...watch the video, you'll know what I mean), we had the third player on the library balcony (the end closest to where the Pak80 is).
lol I help 8 ppl for overseer and I was the only 1 who snipe the RPG guys. All what I want is another guy who have a pak and kill the other enemies. And use the AO3 kickback as mine finishes. Its just very easy as you use yr ao3 take yr time aiming at the head of armored RPG guy its 1 shot kill.