Perhaps lose one combat skill, or at least lower it... For example in mine, her melee abilities are handy, but makes her far weaker than if she kept out of range with her bow, and most of her skills are non combat based, though useful (scavenging/tracking).
I would suggest lowering his bow expertise a bit, OR make him berserker like in melee, where his defense and self preservation is lowered.
As it stands he's a bit of a tower of power, able to use a bow with excellence as well as melee, meaning in a ranged fight he has no handicap, as well as having none in melee. Your mitigating factors don't have to necessarily completely weaken your character, just allow his enemies a chance.
Izzy is at her strongest in ranged combat against other rangers/melee, at middling in melee, though against expert close combat advocates she would stand a lower chance, her biggest weakness is versus spellcasters at any point, with her bow or in melee, as she has little defense against them, and they have plenty of defense (if they have the reflexes :-P) against any of her abilities.
That's the best system, give them an advantage, a neutral area and a disadvantage. A thing they excel against, something they do okay with and something that has a high chance of mincing them.