Building a Troops Outpost City

First off Troops need lots of Food.

Make all 37 Fields Farms. This can generate about 650k food per hour and higher.

if need other resources ship them in from other cities or use 600 ballistas to farm lvl 5 NPCs.

Have multiple Attack Heroes.

Inner Town can have any set up.

Must have:
Relief Station Lvl 9
Feasting HAll Lvl 9
Rally Spot Lvl 9 , Lvl 10 preferred

One city I have 13 Warehouses
2nd City I have 26 Cottages

What benefit are the warehouses really? I have been plundered before. Doesn't seem to keep an aggressor out of my resources?

Ok warehouses are good for a couple things.

One so they can not plunder are your resources.
Two to put up a defensive so your city cannot be taken.

For one, I usually only place Food as protected in the warehouse.
For two, I have lasted Hours taking hit after hit having 1 set up that I have enough food to Comfort Disaster Relief every 15 mins when being Attacked. If have Warehouse set 100% on food and have high enough food production you can use this defensive tactic while you wait hopeful reinforcements or till the attacker gets Tired of attacking.

Please change the warehouse storage to keep ONLY food.
Warehouse is only good for that.

I found that out the hard way when I just started playing...