Agreed. Get all the hoopla out of the way at a specific opening event. The first competitive game at the Amex will be special enough anyway without needing to have Peter Ward cutting a ribbon across the North Stand goal or something.Get the Noddy stuff out of the way early, ie in the friendly, so the team can concentrate on three points in the first proper game.
Having it separate also means that the two events don't 'clash'. One of the reasons for going to the Spurs game will be to see all the legends, it will be a major part of the event - unlike the match itself which will be an irrelevant sideshow (Except of course for those who think pre-season results are important). For the first league game the parade bit would be the sideshow, a bit like the opening ceremony for the World Cup which we patiently endure whilst waiting for the opening game.