The Monkey Village may not look like much, but when upgraded and placed in a defense, they can turn the defense into a WORLD of BLOON ANNIHILATION. Did you guys know that Monkey Villages, when placed near each other, can reduce each other's costs? Anyway, I almost ALWAYS place a network of interconnected and upgraded Monkey Villages in my defenses in the later rounds of BTD5, since even though Monkey Villages take up space, they can greatly enhance your defense in return. You can place upgraded Villages next to a TOTMG and make the TOTMG's range cover at least three quarters of the entire track! Placing a network of Villages in my defenses and making sure my towers are within the radius of the Villages is the reason why I can reach Round 200 with ease if I wanted to. I even place a Village BEFORE I place a Super Monkey, knowing that if I place the Village first it would be easier to upgrade the Super Monkey. A Monkey Village can also grant camo detection to ANY TOWER in its radius (unless if the towers already have camo detection), and even make a Banana farm release bananas faster (thanks to the Jungle Drums upgrade)! Also, the Village's x/3 upgrade, the Monkey Intelligence Bureau, can make all towers in its radius pop ALL TYPES OF BLOONS (e.g. A Monkey Intelligence Bureau can make a 0/0 Dart Monkey pop Lead Bloons)! The MIB (MIB stands for the Monkey Intelligence Bureau) is crucial for BMC defenses, especially when they're against deadly, fast-moving DDTs. They can allow MOAB Maulers to detect and inflict damage on DDTs.
To conclude, Monkey Villages are one of the best towers the Bloons TD series has to offer. They can make a Super Monkey literally the #1 most powerful tower in your defenses AND further increases your chances of getting to Round 200.