level up your soldiers( what to do)

To get the lv3 military books you can only get it in the union shop and the last 2 can only be get to the arena.

You need to have union badge and contribution to able to buy the books
Now ,i will tell you the fastest and safest way to earn stuff like bandages,broken sword etc , which you can exchange for the union badge. Join the floating castle activity. 90 percent of your troops will be return to you. And you can level up your hero and at the same time earn those stuff. Actually its a double purpose and its much better than losing all of your troops while getting into war with another player.

and dont forget also to level up your workshops and upgrade all your soldiers' armor and weapon.if you have further quastion then please mail me again.and i will response any of your doubt.