A pass between Fonte and Lovren across the back as they often do counts as a "long ball" even though it is along the floor and not aimless.
As for "pass completion rate" that is another stat that can be manipulated to mean whatever you want. Southampton this season have made thousands of passes this season more than Fulham, if Southampton's competition rate for example is 3 per cent below Fulham that still means they have completed a huge amount of passes more than Fulham. In one game this season Southampton completed 611 passes and the opposition only had 104!