Maybe add hero (or Cpt Raider if you prefer) for more active gameplay. I understand what this is idle game, but it is boring to only see your troops fight without possibility to control them. Make him active only then player is online and when game is closed he is inactive. Also add an option to choose class for your hero, it can be just like ordinary raiders classes: warrior, ranger, healer. But stronger. Spells (active skills) would be great to.
P.S. : sorry if I made any mistakes. English is not my native language.
 "Idle Raiders")