I'm not sure what youre exactly reffering to about the English mentality;
If it's football violence, I share your disdain for the perception that we're more violent or thuggish than any other nation.
However, as a Sheff Utd fan, I feel you should be able to appreciate a team in spite of a negative reputation when it comes to football violence.
I don't know if England or Sheff Utd have more incidents of hooliganism than comparative nations/clubs - I would love both teams regardless.
If it's arrogance, and the expectation of glory (the kind you might associate with another Sheffield club) then can I ask you, how often have you actually experienced this? The vast majority of England fan's Ive met are the opposite: they have an expectation of failure and are generally overly pessimistic in their predictions.
The biggest problem with the English mentality in my eyes is the sheer number of people who actively dislike the national team.