As you say it is better having less possession but be effective, than having the most possession and being ineffective.
If that's what he means, I'd concur.
That being said, I didn't get the feeling that we parked the bus at any point during our game. We didn't have a proper pre-season to speak of and there were times when we weren't closing down the opposition at the edge of the half-way line.
A lot of their possession came not on our half, but rather them recycling possession at the edge of their half.
I saw a couple of instances of Wayne walking towards the Southampton player on the ball at around the 50 minute, situations such as these lead to the possession stat being as it is currently.
Whilst Mourinho doesn't operate the Gengen philosophy, he does expect his players to close down the opposition near the halfway line. Which considering our pre-season we might not be in a condition to do the entire 90 minutes.
In conclusion, given the conditions and the situation, we really shouldn't read too much into the possession stats at this stage of the season.