Taking a lvl 10 NPC CHEAP
First, scout for a low hero in NPC.
Second, move your best attack hero and 9 more heroes with attack of 100+ into the attacking city. You will need to move out your Political hero and will not have a mayor during the taking.
Third make sure NPC is within 2 miles from your city.
First wave:
90K archers, 3K warriors, 2Kworkers, 3K scouts with best attack hero.
Immediately after send 30K warriors times 2 waves
Immediately after send 20K warriors times 7 waves
Heal when waves hit.
As soon as first waves gets back, send:
30K archers 20K warriors Times 2 waves
Immediately after send 20K warriors times 8 waves
Continue waves like this until the NPC is yours.
Remember to heal after each wave of hits is completed. Relax but concentrate. You have time so do not worry about it.
You will need @ least 92K archers, and about 350K warriors. Plus the first hit fodder.
You will lose a very small amount of archers and only about 40K warriors.