Let me just say that I hate the idea of the game manipulating the concept of “random” behind the scenes. Random should be random. A risk should be a risk, and should succeed and fail on its own luck. If the troops are not balanced properly given the average expected results, then fine – change the spells so they’re more in line with the length of the streak you want to see. It feels wrong and dirty to have some “invisible hand” manipulating the very meaning of “luck” itself.