It was tactical, yes.
I would argue that the tactical bit was starting Shaqiri in the first place.
It was a wildly imbalanced starting line up that encouraged Southampton to come out of their shell. Sit back and allow the likes of Shaqiri, Mane, Bobby and Mo to run riot or meet fire with fire. Hughes went with the meet fire with fire option and ended up fighting heat seeking missiles with pea shooters.
The best bit was Jurgen's 'we didn't have time to work on the defensive shape because of the weather line'
The truth is that parking the bus is now a gamble because we might overload the attacking positions, however we might play our normal game and look to dominate.