Guys... Godclone already said he plays at King difficulty. Arguing with him about map settings is pointless.
Can you quote me on that ? No , you can't because no matter how you read Deity it will never transform into king .
Regarding map size, large map is AI bonus because of his happiness bonus the warring AI will snowball into a superpower able to maintain x number of cities more than you and out tech/out produce you by a vast ammount . And if you want to play economic war on deity large maps , you are doing it wrong . The AI advantages snowball and you will never catch up . One AI almost always gobbles the other AI and snowballs into a superpower only to overwhelm you .
Regarding your map settings i found 2 things . By the time my second warrior gets to my closest AI his city strength is so high i cant scratch it with 5 archers and 2 warriors, but he can't kill any of my units regardless of how many units he throws at him .
So i will adapt my strategy around catapults since without them it is unrealistic expecting to capture any cities . Beeline iron working and settle on iron resource, if not available on capital, building meanwhile barracks, armory and national wonder for unit xp , making catapults and upgrading warriors to swordsmen before attacking .
Because the quick speed is unrealistic regarding warfare , the main reason i play standard or slower speeds is that until you build and get any units to an enemy they are so far behind technologically their irrelevant vs cities , even if you can hold off his army in a good position .
The fact that a strategy needs to be adapted to the map settings is perfectly fine, its part of the things that make it a strategy . Besides its mostly jumping to the point you were in slower speeds by the time you were on your 3rd AI war .
Unlike cheating -> restarting, reloading , and abusing ******** AI trade, of GPT, resources /turn while declaring war or accepting ridiculous peace treaties . Which is the OP answer to "everything" making his strategy a cheating guide rather than actual strategy .
P.S. Playing any game on nothing but the higher difficulty setting is a waste of time, because most things you learn in lower difficulties is bad gameplay on higher .