Besides unlocking the caraters(which is not cheats) there only a few things that can be done here are some I have found

RANDOMISING SHOPS/HIRED TROOPS
Save the game twice(1 just incase you don't like what you buy)
And kept on loading again and again to get good stuff

MORE XP
When in the story line you get experience bar come up with like +150 you can just go back to the world map and replay the mission over and over

NOT A CHEAT A HINT
When you go into a battle your troops health declines at a set rate so try and weaken the other troop with moltars or archers befor attacting