I think it would be nice if the villagers actually defended themselves against zombies to an extent. I am a little tired of finding villages completely void of of life because zombies killed all the villagers. I think that guards should be added to villages to protect the village. Some villagers should still die, but they shouldnt all be killed.
Oh yeah, I did forget about the iron golem, but even with the iron golems, in my villages most of the villagers end up dying eventually.