#2 Toothless attack
United's top three goal scoring forwards in the 2013-14 season remained Van Persie, Rooney, and Chicharito. While Moyes played a lot less attacking style as compared to Sir Alex (Sir Alex drew his last match 5-5 against West Ham), he also suffered from an apparent loss of form from key players.
Van Persie had scored 26 goals just a season ago, almost handing United the Premier League all on his own. He could only come up with 12 in the 2013-14 season. Chicharito was almost never played by Moyes, and he scored only 4 (as compared to 10). Rooney came up with the most goals (17), forcing Moyes to play him as the main striker.
Mourinho's team is faring no better. Having dropped Sanchez and Lukaku (both have had 30 goal seasons previously) at different times this season, he has found refuge in Martial who he has now started playing more regularly, and sometimes also as a central striker.