It'll probably all degenerate into utter chaos anyway, but hopefully we can sort out a few outlines to speed the whole process up for everyone and get back to the good stuff.
If nothing else, I'll be referencing this post myself to try and remember how to try and do this!
The Maps
Shatter - The ideal choice as it would seem to be the only map in which every single achievement can be earned.
----Mantis - The only map with them. There is one under the ramp of each teams starting spawn point.
----Detachable Turret - Again, the only map with them. There are two, both located on the walkway between the two main structures. These respawn quite quickly.
----Warthog - Near each teams starting spawn point. It's not the most bumpy of maps, so getting air may be a problem.
----Gravity Lift - These seem to count as Man Cannons, and so should enable ODST, Special Delivery and Clay Pigeon. Not sure where they are, but I'm sure they are there somewhere!
Harvest - This may be the best map for getting "Now They Fly?". Lots of Warthogs and plenty of bumps. Even a few areas that can be used as ramps.
Also features some gravity lifts in the centre building, which again may enable ODST, Special Delivery and Clay Pigeon.
Wreckage - An alternative to Harvest, but in all likelihood not as good. Does feature Warthogs and actual Man Cannons, but doesn't seem especially good for getting warthog air.
What I'm hoping to do is work through peoples achievements alphabetically by their gamertag.
That's not a scheme to get mine first and bugger off, just seems the most straight forward way.
Priority should first go to the Mantis achievements, as they are slowest to respawn.
Ideally, upon hopping into a Mantis, it would be best to move to the centre of the map, near the turrets. This should make it as simple as possible for people to gather for a squishing and return to be flattened again.
Once a person has got the Big Foot achievement, they can hope out for the next person to have their turn. We'll be in teams, so the exchange should be pretty quick and two people can be working towards Big Foot at any one time.
With that done, we'll go to the process of David and Goliath and Pump Your Brakes.
If someone already has Pump Your Brakes, but not David and Goliath, they should go first as you can board the mantis, use a grenade and get the achievement without actually destroying the Mantis.
During the Mantis respawn period, we can then work towards detached turret kills and the 3 man cannon/gravity lift ones. Possibly "Now They Can Fly?" if the terrain proves hilly enough.
So that's the idea but since there are communications limits... I'm sure it'll all go to Hell pretty quick.