Sounds like your friend might think Sherwood's a good managerExactly - if you talk to him about the game in general, he know tactics, players, managers, history, European and world football really well. He knows the stats and current form of loads of players and teams.
He supports a League 1 side so has no bias against Spurs - I think it's a case of him not having a singular interest in the Premier League and so probably getting some of his opinion on it from the media/pundits etc.
Because, you know, win percentage and all that jazz