I too am still lingering on 3 star. I'm trying to complete a ML season before bumping it up (I can't change the level now, anyway, I passed the halfway mark), and sometimes I absolutely struggle to score with Arsenal, and other times I can bang 5 out. The problem for me, I think, is that I play with my favorite team, which makes me so tense that I play "to not lose," rather than to win, if that makes any sense.
For example, I was having fits scoring only 1 or 2 goals a game for about a 8 game stretch, then played a 4* game with Barcelona (whose system and players I"m totally unfamiliar with) and scored 5-0 (granted, I was playing Malaga or something), and I just thought that I was playing more relaxed b/c it wasn't as personally painful if I and Barcelona lost than if it were Arsenal.
On the other hand, my last game for Arsenal was in the WEFA CL semis v. Real Madrid. I've never played such a difficult game in my life, yet won 2-0 (I had 3 shots on goal, 1 from a FK, the other two were cracking shots that I let loose on the only two decent through balls I could get to my forwards near the box). Real Madrid had 15 shots on goal and completely kicked my butt...they missed enough close shots that they easily could have dropped 5 on me.
I don't have much point to this thread other than to share my own fits with my 3* ML season and to say that I'm intrigued that other players seem to think that on the higher levels the computer is more aggressive and leaves more space on the pitch for attacking.