Lots of things are much more difficult at Brentford than at Tottenham, but building a united, hardworking, no ego internal culture is not one of them.
That's much EASIER at a low budget neighborhood club than it is at a place where the squad is bigger and more diverse, the players are more famous and more highly paid, the fan and media scrutiny is higher, etc.
And Frank had been an assistant there for nearly two years when he got the head job, and led them in the Championship for two and a half more before they made the Premier League.
Frank is not walking into Spurs with the command of the room he has always had at Brentford. Gaining that credibility to dictate the culture is going to be a major challenge.