I used to struggle and fail in MOAB Graveyard until I invented the Lazy Man Strategy. It is somewhat similar to other strategies on the net but much simpler. The track view is below.
First place 1 Monkey Village near the end of the track and upgrade it to 2/1 (Jungle Drums/Monkey Fort). Then place Spike Factories and upgrade them 1-by-1 to 2/3 (White Hot Spikes/MOAB SHREDR). The MOAB SHREDR is particularly important. Do as many as you can, then start the round. There will be 10 MOAB's in the first round.
After the first round, put a Super Monkey on the first bend and upgrade to 2/2 (Plasma/Epic Range). Continue doing this throughout the second round. Buy a Bomb Tower and make it 2/3 (Frag Bombs/MOAB Mauler). Place before the second bend. Continue building Spike Factories and upgrading to 2/3. There will be 6 BFB's in the second round.
Now, you should have a lot of Spike Factories all in the radius of your Monkey Village, a Super Monkey and a MOAB Mauler. Drain your money before starting this round. If you have spare money buy more Bomb Towers and place near the first. After the first two rounds, you will be feeling quite confident, maybe over-confident but ZOMG's are extremely difficult so be careful. Just 2 ZOMG's will come but they will test your defenses to the last spike. After the first one is beaten you know you're safe. Just let out a sigh of relief and sit back and relax. Claim your victory, tile, coins and bloonstones.
Thanks for reading! Please post requests for missions in comments.