Tactical Help for Arsenal...

[Gunners4Life]

Hi guys, I'm in my second season of FM 10 and basically i'm having trouble getting Cardozo and Dzeko to score regularly as a lone striker. I managed to finish 3rd in my first season and I'm currently 2nd in my second season after 8 matches but haven't played any of the big 4 yet. My strikers have trouble scoring regularly though. Also scoring against the weaker teams is fine but they seem to struggle a lot when up against the likes of Chelsea and Man U. I always lose by around 1 or 2 goals against them and most of the time fail to score at all. My current formation (4-1-2-2-1) with my best 11 is as follows:

Almunia - Sweeper Keeper - Defend
Sagna - Wing Back - Support
Vermaelan - Ball Playing Defender- Defend
Kacar - Central Defender - Defend
Clichy - Wing Back - Attack
De Rossi - Defensive Mid - Defend
Fabregas - Advanced Playmaker - Attack
Rosicky - Central Mid - Support
Van Persie - Inside Forward - Attack
Arshavin - Inside Forward - Support
Cardozo/Dzeko - Target Man - Attack

Fabregas is primary playmaker, and striker is target man with supply to head. The team usually plays a fluid, balanced formation with the rest of the stuff tweaked differently depending on the game. Any tips as to why the strikers can't score frequently? also any tips to combat conceding against the big 4, and also scoring against them? Any help will be much appreciated !!!