I like ur plan! Just remember to have MASSIV troops so you will be able to take down a lot!
You`ll gain shitload of prestige and honor if you can pull this off. Also you whould be a feared power player!
Godspeed to you
Let us know if its anything you need!
Regarding the 1 city left you should have ust farms... maybe 1 iron, 1 wood and 1 stone farm.
Also as many Barracks you can! You only need, Feasting hall, Acadamy, Rally spot, beacon tower, relif station and Inn + some cottages(max10 if not less)