These will help you defeat npcs.
Flavored bacon will reduce travelling time.
Emerald poison will reduce npcs strength. You can send lesser number of troops for each attack.
Trekker's pack will increase the amount of plunder.
To make them, you need to use the World map and go to the Capital where your main city is located.
When you have entered the capital, go to Craftsman Association.
You will see the above list of things there. Click any item you wish to craft and the above menu will appear, showing you the resources needed for the craft and how many you can make.
No npcs to attack in the viccinity, so attack the mearest one which is on the upper left level 11 Ashka brotherhood.
Note that travel time is 5 minutes and 25 seconds. The 2 minutes 55 seconds time reduced is by having the marching time reduction blue runes.
Use flavored bacon and emerald poison.
Note that marching time is only 3 and a half minute.
When you use emerald poison, you will see the circled item in the report. I used the Level 1 poison. Poison is used so that I could send smaller sized troops than the usual, which also saves the amount of food needed for marching, and still can annihilate the camp.
When that camp is cleared, it will make way for a new level 11 camp in the next npc refresh. That is why I annihilate level 11 camps.