In the final map of the DA campaign, my starbase was attacked by a DreadLord ship with no defenses. However, with its 300+ beam attack, I knew the starbase would die. The starbase had sufficient attack to destroy the medium ship in most cases, but I noticed that as had happened previously with other combat, the DreadLord ship always escaped with 1 HP when it should have also died. A constructor upgraded to a high attack ship faced a similar fate, but I accepted that maybe that ship type was unable to kill on its own.

What I discovered today (https://www.galciv.wikia.com/wiki/Ship_design_strategies) was that a new DA combat rule is that if both ships would normally be destroyed, the "strongest one" survives. (Is the strongest ship determined by attack, size, or HP?). I guess that changes the late game strategy slightly because a smaller ship will lose to a larger ship if both have massive weapons values. Does the new rule prevent "ties" in combat now?