After playing 9 games and only lost once, I created an ultimate strategy for MoneyWalls.
STEP 1 - Kit
It's important to choose a good kit. Here's a list of the kits.
Swordsman: Medium boost at start, but gets useless before the wall even drops.
Money Bag: Same as Swordsman.
Tank: A leather set (12 iron) has about the same armor points as the Tank set, so it's kinda useless.
Scout: As long as you don't get hungry, it can really get you out of a deadly situation.
Defender: Obsidian blocks are very expensive, so this is an epic defense boost.
Healer: When you're low on health, just splash yourself and back you go on the battlefield!
Archer: Ranged weapons are way more useful than you think.
Enchanter: The main reason of killing mobs and buying non-enchanted weapons and gears.
STEP 2 - Iron Tokens
Get yourself at least 12 irons as fast as possible. You'll need the leather set to raid the gold generators. You should also get extra iron for food, because you get hungry really fast.
STEP 3 - Gold Tokens
Get at least 12 golds as fast as possible, and then buy a Sharpness I Stone sword, because deals 0.25 more damage than a regular iron sword. Now you're ready to raid the diamond generators! You can get more gold, however, for other things such as golden apples.
STEP 4 - Diamonds!
Now you should get at least 24 diamonds for a Sharpness I Iron sword and a full iron armor set. If you have more, get a diamond pickaxe. Now you're ready to go on the battlefield!
STEP 4.5 - Guardian
You probably still have a minute or so left until the wall drops. If your wither king has no defenses, you'd better build some defenses quickly. Bricks are good choices, but obsidian blocks are much better. Note that you should only save up for obsidian if you have Step 4 finished, and you have plenty of time or a fully upgraded diamond generator. Obsidian are very expensive, and diamond generators are very slow. This is where the Defender kit comes in and does it's job.
STEP 5 - How many emeralds?
On some maps, you can collect as many emeralds as possible, then just run away when someone that has better gears and weapon than you runs towards you. But on maps like Prison, there's only one way in and out, so you must know how many emeralds you need and don't be too greedy. If a full diamond set player suddenly climbs up the ladder but you only have iron set, you're probably going to get killed and lose all your emeralds, and in the worst case, won't respawn. Here's some numbers to follow when getting emeralds.
24 EMERALDS: Regular diamond armor, Sharp I diamond sword
44 EMERALDS: Prot I diamond armor, Sharp I diamond sword
64 EMERALDS: Prot I diamond armor, Sharp II diamond sword
64+16 EMERALDS: Prot II diamond armor
64+28 EMERALDS: Prot II diamond armor, Sharp I diamond sword
64+48 EMERALDS: Prot II diamond armor, Sharp II diamond sword
64+64+16 EMERALDS: Prot II diamond armor, Sharp II diamond sword + 1 God Apple
STEP 6 - Freeplay!
From now on, it's free to go! You now should have enough defenses to attack the opponents, or defend against incoming forces that are trying to assassinate your wither.
And that's my strategy! If you have a better strategy, please tell me! I'm always up for improvements and feedback.
STEP 1 - Kit
It's important to choose a good kit. Here's a list of the kits.
Swordsman: Medium boost at start, but gets useless before the wall even drops.
Money Bag: Same as Swordsman.
Tank: A leather set (12 iron) has about the same armor points as the Tank set, so it's kinda useless.
Scout: As long as you don't get hungry, it can really get you out of a deadly situation.
Defender: Obsidian blocks are very expensive, so this is an epic defense boost.
Healer: When you're low on health, just splash yourself and back you go on the battlefield!
Archer: Ranged weapons are way more useful than you think.
Enchanter: The main reason of killing mobs and buying non-enchanted weapons and gears.
STEP 2 - Iron Tokens
Get yourself at least 12 irons as fast as possible. You'll need the leather set to raid the gold generators. You should also get extra iron for food, because you get hungry really fast.
STEP 3 - Gold Tokens
Get at least 12 golds as fast as possible, and then buy a Sharpness I Stone sword, because deals 0.25 more damage than a regular iron sword. Now you're ready to raid the diamond generators! You can get more gold, however, for other things such as golden apples.
STEP 4 - Diamonds!
Now you should get at least 24 diamonds for a Sharpness I Iron sword and a full iron armor set. If you have more, get a diamond pickaxe. Now you're ready to go on the battlefield!
STEP 4.5 - Guardian
You probably still have a minute or so left until the wall drops. If your wither king has no defenses, you'd better build some defenses quickly. Bricks are good choices, but obsidian blocks are much better. Note that you should only save up for obsidian if you have Step 4 finished, and you have plenty of time or a fully upgraded diamond generator. Obsidian are very expensive, and diamond generators are very slow. This is where the Defender kit comes in and does it's job.
STEP 5 - How many emeralds?
On some maps, you can collect as many emeralds as possible, then just run away when someone that has better gears and weapon than you runs towards you. But on maps like Prison, there's only one way in and out, so you must know how many emeralds you need and don't be too greedy. If a full diamond set player suddenly climbs up the ladder but you only have iron set, you're probably going to get killed and lose all your emeralds, and in the worst case, won't respawn. Here's some numbers to follow when getting emeralds.
24 EMERALDS: Regular diamond armor, Sharp I diamond sword
44 EMERALDS: Prot I diamond armor, Sharp I diamond sword
64 EMERALDS: Prot I diamond armor, Sharp II diamond sword
64+16 EMERALDS: Prot II diamond armor
64+28 EMERALDS: Prot II diamond armor, Sharp I diamond sword
64+48 EMERALDS: Prot II diamond armor, Sharp II diamond sword
64+64+16 EMERALDS: Prot II diamond armor, Sharp II diamond sword + 1 God Apple
STEP 6 - Freeplay!
From now on, it's free to go! You now should have enough defenses to attack the opponents, or defend against incoming forces that are trying to assassinate your wither.
And that's my strategy! If you have a better strategy, please tell me! I'm always up for improvements and feedback.