Relax about the ribbons.
First, posters have noticed that nothing says the the Recruit Clayton and Marauder achievements cannot be earned in Private matches. That means that people on this site could play 5 against bots.
That also means that while you're working together for those achievements just play together for the ribbons in Versus, Beast and Horde.
Like above, I lack the revive 3 teammates at once. But if you're playing with people you know and can talk to, it should be much easier to coordinate that with Beast Mode on Easy or Normal. This applies to most of the other trophies.
Also, 7th, play the supermarket section of the campaign on (solo?) Insane. Intentionally poorly shoot at the Drudges to get them to mutate. You should get at least 3 headsnakes to spawn before you finish that section.
As for quick kicker, play RAAM's Shadow again, in that school section where the Tickers and Savage Tickers (or Tickers off the Cobb). Just play it on Easy or Normal, and kick away when they come at you.
For I gotcha, if people on this site want to play for the Horde Achievement with this DLC, we should also play one game on Easy, and thrown on Friendly Fire. Just down the other 4, and pick them up. You can only do this twice per round, but it should work.