You guys need to take into account that Mourinho is not the type to pursue a pre season win record. He is the type that will use this pre season match to get the best possible scenario for the new season later which means that he might experiment lof of strategies. Take alook at the previous Chelsea match and you will see how they play unlike their usual style.
The same thing with Van Gaal , he is the type that will experiment the best composition for next season which mean both Chelsea and Manchester United will probably not win the match. Joca's suggestion is much more likely to happen (references below)