I don't think that nerfing warriors and buffing mages is a good solution to 'weather the storm'.
I already feel like mages are OP. Taking some of the tankiness away from Man at Arms and giving it to the magic skills just exacerbates the problem. I agree with splitting the resistance into 4 different talents, and making each talent stronger. But I would rework them to scale off of Willpower or Bodybuilding (or both), so that mages don't have a monopoly on their benefits.
So example:
Water Adaptation
Each point of Willpower and Bodybuilding increases Water Resistance by 5%
