I personally think that u should be able to control the amount of soldiers used. For example when u click attack u type in the amount of soldiers that u want to use. You can use all ur soldiers in one attack for an almost ensured victory.
No, this way you can use 1 soldier per attack and use pots to ensure victory, then have a huge payout. I get 24m first attack on Haunting, and something around 21 last hit. I would be making billions per unload.