A good thing about this game is you do not have to worry about losing any soldier.
Your rank will depend on the number of Trophies that you could collect (top right image). If you perform Raid on other players i.e battling them, the worst that could happen is just losing Trophies points. If you won the battles, you will get more points. No Heroes will get wounded or die. Really a relaxing game because all you have to do is battling in the provinces and strategise on levelling up your Heroes.