That is indeed a possible option. Extending it out to the case of where a given role allows a range of skills that does not encompass the entire set, is there a way to set the menu options? To use two slightly artificial example:
Infantry - Skill 1: [Combat or Physical] Skill 2: [Combat or Damage]
Specialist - Skill 1: [Social or Mental] Skill 2: [Combat]
If I have someone who's chosen Infantry, Combat, Combat and then changes their role to Specialist, it would be nice to change Skill 1 to be undecided (or the first valid option) and leave Skill 2 as it is. Alternately, is there a good way to clear choices just so that I avoid having an invalid setting?
And I know that the answer might be "No, you can't do that", but I figure it's worth asking.