I would implement the teaks against the 4-2-4 or attacking AIs a bit ealier when playing away from home.
Close down/ Always on all player WITH the ball( in the build up)
- Fullbacks
- Central Midfielders
And Tight Mark/Always on all players WITHOUT the ball( in the build up)
- The Wingers
- The Attackers
If they use a DMC you have to decide what to do. Is he responsible for the build up( close down), or is he a passing option for the FB and MC( the Tight mark, also in tactic by the FC)
You could also start playing man-man marking( specific, by position) all over the pitch.
Also, if not implementing the tweaks above, have a look at their MCright( mostly him, only sometimes the MCleft) and how much further up in the pitch then the ball he is. Use hard tackle and show weaker foot on him if he is very advancing. Also Close down /always on the other MC
Apart from that I do not think I would lower the mentality of the defenders. This would only results in even bigger gaps between our Fbs and Wingers
One last thing.. Often the probelm lies in not being able to score 2-0 when being in charge of the game. Focus on that as well