Neither. James isn't an alpha male -- I don't think the "alpha male" idea is even helpful in thinking about James, even if we could get past the problem that "alpha male" can be understood in at least two very different ways -- and I don't think he's mentally frail either. (When I first caught a glimpse of the thread title, I was hoping it would be "Alpha male or alpha
fail".)
Not that he has completely failed. I think it's clear that he's had considerable influence on how some other HMs see things -- such as Ricci's otherwise odd claim that Audley cooked to get screen time.
I think he also played a key role in getting the "rude" meme to flourish this year. Gary is "rude", HM after HM says (though, importantly, not all of them); other HMs are rude, but not "rude", it seems. "Gary is rude" is how they rationalise their own rudeness and worse towards him. Then, having used up their supply of "rude" on him, they fail to notice how rude they often are to each other.
Anyway, since James's presence has made the show worse for me as a viewer, I do not think he has been a good housemate. For me, this series would be better if James had not been picked as a housemate.
However, I will say one thing in his favour -- and it is not, imo, a small thing. The other day, James said he'd always thought he didn't care what other people though of him, but he'd earned in CBB that he did care.
James seems seriously lacking in self-awareness, but he deserves points for that. I don't think I've
ever seen an "I don't care" HM come to that sort of realisation before.