Quote:
you cant be immune to fire too?
I think perhaps a better reason to drop ice (for a full str build) is the fact that its main benefit is physical defence, both from frost guard series, and cold armour series.
Think about that for a moment.
A full STR build is inherently physically strong. In fact a lvl 80 full str archer has around 20,000 Hit Points !!
Fire, not only provides the ability to do more physical damage to opponents, (flame body series) it also provides resistance to magical attacks. (fire protection series)
The later being far more useful to a character with 20K of HP, than having added even more physical defence. Which, in my opinion, would be a waste.