The brain is incredibly plastic. In different degrees, it has been observed that neurons around a destroyed area mitigate the problem by taking over lost function.

In addition, abstract processing in the brain occurs over larger areas (think large neural networks). It is not established how exactly. It can be reasoned that to achieve some form of thought, followed by action, multiple sensory modalities have to be integrated. For this large, spatially divided, parts of the brain are necessary. Personality and intellect are therefore likely an emergent property of the entire network, not so much restricted to the frontal lobe.

It's a shame he is not thoroughly studied. I'm curious to see the actual extend of the damage. I hypothesize that his seizures are a product of plasticity around the damaged areas.

Yes, alterations elsewhere could most certainly have an impact on personality and intellect - but certainly a person with severe frontal lobe damage suffers more profound personality changes and working memory deficits than someone who experiences damage elsewhere, correct? I'm reminded of the story of Phineas Gage who had severe injuries to his frontal lobes, and according to people who encountered him displayed poor judgment/impulsivity for the rest of his days. There have been challenges to these reports, with some saying that Phineas Gage was very functional even after the accident. I'm inclined to believe that the truth is somewhere between "Severely disabled" and "Perfectly functional," which means some aspects of reports about his personality changes are accurate.

Yep, that seems fair to say. Must note that it seems that the damage that Phineas endured was much more substantial.

Considering the complexity of personality and behavior and our lack of understanding of their representation in the brain, I wonder how far we would get than this type of anecdotal evidence if given the change to investigate. Personality tests are mostly, if not completely useless.