Trade Ironheart Preserver defenses for HP

Having better defenses than their pals (or even defenses that
were as good!) meant that the player was encouraged to prioritize
the pals first, generally killing the preserver indirectly
(through the injury bond) without ever bothering to interact with
them. A monster that the player shouldn't bother to attack is a
terrible, terrible design.

More hp means that they can actually soak up the damage the player
deals to their pals, and worse defenses mean that you can do more
HP damage by attacking them than their allies.