Well, Defense Breaker applies on HP and Armor (it makes the enemy take ~40% more incoming damage if my calculations are correct 5Head) so swapping hp and armor won't really help, plus armor from jug is different from armor from Armament or Neuro-Fiber Armor and Kevlar Vest. The Jug's armor has some kind lf resistance to low dmg zombies for example fast zombies deal only around 3-4 dmg to his Armor. However I don't know if the HP from the jug has resistance to low dmg zombies because i don't play fast zombie.
@scrungus That's actually true, most of the jugs are just RPG spam and pray for RNG, It would actually be cool to see a jug use his minigun more often, the only time the minigun is better than RPG is when you get to a place where only fasties can come up to you