Been working on this for a while, but must give thanks to AmyHero6 for advice on the matter of melee/ranged ratio. This was mainly to help my alliance, but no reason you cant all have it.
Now most people think that the best defense setup is 75/25 melee to ranged ratio, With 1 fire moat, 3 slits and 1 mach or 2 slits 2 machs depending on your alliances opinion, And although this setup is good, it can be beaten when your offline, which I proved to you in my guide on beating the wall. The setup i'm about to show you is almost impossible to be beaten. Please note that no this can't hold against 6 waves, but literally nothing can...
What is the setup?
You will need veteran swordsman on the wall, and veteran composite bowmen in the ratio 80-20 With all lime bombs on the wall and a fire moat, here is why :
How does it work? Ok so your 4 net percentages on the top are your wall, melee strength, ranged strength, gate and moat, we are defending a flank so forget about gate
The big thing is here that your wall, ranged strength, and moat can all be reduced to 0 with tools and a good comm. The only thing the enemy cannot tamper with is your melee strength, which means that is what we want to increase. 4 slots of lime bombs increase our melee strength by 132% and assuming we have a 90% melee cast, we have 322% melee strength altogether.
Now the reason we have some ranged soldiers, is because that means they will be forced to use mantlets, and then either choose the reduce your wall protection or moat protection, if we had used all melee troops, they could of used tools to reduce both. They are going to reduce whatever is strongest, which will be your moat since were not using wall tools, now it varying depending on the cast you have, but you will be having say 100% wall protection.(Assuming here the comm and cast wall percentages are the same) This combined gives your melee troops 472% strength against ranged soldiers.
Now the reason we are using veteran swordsman, is because they are the melee troops with the strongest combat strength against melee soldiers which is 72.
Altogether 472% of 72 is 339.84 strength per vet swordsman. Now at level 70 we can put 320 men on the wall, 256 of them will be vet swords, giving all your men 86999.04 strength against ranged soldiers.
Assuming the enemy has a 90% ranged comm. he will need 283 deathly horrors to beat your flank. 262 veteran deathly horrors or 229 cave hunters. They can put 256 men on the flank, so the only way they are going to beat you is if they have an army of cave hunters. And if they do happen to have an army of cave hunters,which only a few people in the game have, if you are online you can crush them by going all ranged and slits.
Why do people not use this setup all the time? Well i'm glad you asked! 2 reasons really. 1. Lime power bombs are so hard to get and then stockpile. You would need over 80 minimum to cover all your castles. 2, If you need support, it is VITAL you are only supported with veteran swordsmen for melee. Otherwise other troops will go on the wall and get rid of the vet swords. meaning you would lose the flank.
Why it can still be beaten? There are 2 ways this setup can be beaten, 1. Of course the 5th and 6th wave, then you pretty much have no chance. 2. Flank gems, they may just beat you with them, but people favor cy gems much more so you probably wont see that ever happen.