Which items work well / don't work for Boss battle's?

[DGDobrev]

Well, if you do the same thing in all situations, the outcome will be the same, because the AI playes the same way and does the same calculations. This is how you can mold the game to your liking. You change something - like waiting with a unit, digging after a certain unit has/hasn't moved - and there you go, the game suddenly changes.

Your numbers seem accurate as well. When the boss retaliates, it does 2.5 times less damage, which is clearly shown here.