Please note that as per the help file on them, the fact that attacking squads attack at one level below their actual level means that you are literally throwing your poor soldiers' lives away if you use level 1 soldiers in an attack.

You need to actually level up your soldiers by having them guard a working mine in order to get them to level 2, where they can actually do some good in battle.

Penned by My hand on the 19th of Glacian, in the year 688 AF.