The angel knight has a knock back, which alone makes it the best unit, here is a simple explanation of how to get it, view the credits and instructions to unlock the hobbits, then go to level 6 and spam hobbits from the start, then with each race get the maxed research, i must warn you its boring but its the fastest way at 4000 exp a minute
 "Hedgehog Launch 2"){kind=icon}
 "Post it Draw it"){kind=icon}
 "Epic War 2"){kind=icon}