I don't see that at all. Every team has the underdog mentality drilled into them. That's not anything new. Its the first thing you hear, even from championship teams.
As for being physical, I think you can thank the defense for that. Guy was hands off in regards to the D. He also clashed with chippy players on the team, so what does that tell you about how he wanted tough teams?
Doug "I don't like fighting...it doesn't belong on my field" Marrone deserves credit for hiring two good defensive coordinators (and that's assuming he was the driving force behind both of those hires, which I'm not entirely sure of). And that's it. He honestly did absolutely nothing else positive for this team. This is why I say that when you look at it as getting the most out of what they were given, he really is the worst coach of the drought era. The other guys had their issues, but no coach squandered as much talent as this jobber.