I gave up worrying about the standard of our pre-season opponents a long time ago when it was explained to me, by people far more qualified to comment on such things than I, that pre-season friendlies were only a small part of a much larger closed/pre-season preparation programme and unless your aware of the type of day to day training the squad are doing then it's near impossible to gauge if the balance is right.
Foreign training camps and pre-season tours are a luxury and are more about building player morale, team spirit and giving the fans an excuse for a wee jolly. That's not to say they can't be an important part of preparations, but they achieve nothing which can't be fulfilled in other more convenient and cheaper ways.