ITT: not being able to position your units safely and account for enemy reinforcements is Intelligent Systems's fault.
Honestly, it's not really about unit positioning, it's more like you're better off just not deploying a healer and using items to heal. It's not tactical at all. Just... A numbers game. Oh what's that? My unit has 10% chance of being hit AND takes 5 damage? Okay. I'll just rush ahead and be in range. They'll suicide on him/her.