About defense òf city I recommend to build 7000 archer tower, 10k archer inside city. Army should build with 10 barrack per city except for military city ( 12 barrack with all farm) Economic should have 100k each resource the rest of resource field will be farm.
Praying is also a good key to get prestige faster, you should create archer tower and construction in city in the same time. Make a lot of army will boot your prestige pretty much