[Micah]

Given the abysmal base 8 defense that Wyrms have the 2 points isn't going to make a whole heck of a lot of difference. Early game Wyrms survive combat through the awe/fear combo, regeneration, and a bit of natural protection. Their defense might save them from 1 attack out of the 20+ that will hit them if they're surrounded by size 2 units, which isn't at all a significant value.

The repel damage is also fairly insignificant, as the repel has to hit and penetrate the Wyrm's protection to matter, and even then it only does a single point of damage. The increased kill rate will generally be well worth the few points of damage, as it helps cause the assailants to rout and flee before they have a chance to kill it.