Thanks for all the valid criticisms!
Unfortunately for our team, we started a day late to the jam due to personal issues, and the idea was just kind of scrambled together on the night of the first day. I think one of the big mistakes I made with design was the inclusion of heals when killing an enemy with a risky play. After a few waves, there's pretty much no incentive anymore to even play with a real strategy. As for what you pointed out though, the idea was that the play of choosing a position with knowledge of your attack pattern beforehand would be punished with less damage, but I do suppose that it wasn't really punished as well as it could have been!