Interestingly, I think the big thing might be that he doesn't /really/ want to be in charge, he just feels like he has to.
I mean I could obviously be wrong - his actions at the country road definitely have him leading and he's very, um, aggressive about not listening to people, haha. But the rare times that he's found himself vulnerable have been times he can /really/ relax. Like how relaxed he was when he was recovering at your house.
...but then that might be even /harder/ for him to accept, haha.
Doubling down on this is that Bernard is getting a bit more aggressive and was already a central leader, so he may be a more natural fit for Alpha.
All this is of course theory, haha, I just really like contemplating this kind of stuff :D