Leveling help for a level 15 warrior

[Jagrapoite]

I am having a hard time finding a place to level my warrior, without losing vaulable units. Is there a leveling guide? I am the main quest of queen viloita(spelled wrong) where she is not talking. I get to the freedom islands and get half of my army destroyed. I have picked up every plus leadership flag i come across, but I seem to have killed everything i can including the underground, eastern and western islands. I am playing on easy. Any tips to where to level? I would hate to have to pick up a new game after playing for 3 months. Ty for your help. I am level 16. leadership 7769 max rage 54