Well if your problem is in defense, like I said before, the answer doesn't have to be stop playing manual but instead adjust the CPU sliders to even things out.
I just won the league in CM playing as Chelsea, on default settings not using manual, and the only way I did that was by scoring a shit ton of goals. Even though my defense consisted of outstanding players, being solid in defense in this game on default settings is near impossible IMO because the defensive part of the game simply isn't good enough against the CPU AI.
So either drop the manual settings so you score more goals (player stats still really shine) or adjust the CPU sliders so that you don't concede as many goals.
I don't want to adjust CPU sliders to be honest, once I get into that whole area I'll end up spending more time mucking around with them than enjoying the game.
That said, I've been fine with it up until this last week. I've only been playing friendlies with random teams, but I've generally done okay - won some, drawn a lot, lost some.
But this past couple of weeks, it's as if the COM has gotten a whole lot more aggressive. It hasn't as there hasn't been a patch, but it feels that way. The game is starting to thrash me almost every time. I just turned it off when I went 4-0 down against a lesser team.
I can barely score at the moment either. Once I get to the final third, all my players seem to just stand around doing nothing, being man-marked. And at the other end, I can't stop the COM from scoring, particularly in the last ten minutes. It feels like the game just scores when it wants and you can't do anything to stop it.
It's a great game, the AI on World Class is amazing, but I'm not enjoying it because I'm so bad at it. I can't even contemplate doing a Career Mode because I'd get sacked.
So I dunno. I did okay at the game at first, thought it's fine, I'll improve the more I play and learn the game, but I'm not improving at it at all. I'm now getting thrashed every other game. I mean I lost 8-0 yesterday, and twice switched the game off tonight when I went 3-0 and 4-0 down respectively. Switching it down to Professional level just doesn't have the same feel to it, so I'm not sure what to do with the game at the moment, because getting hammered all the time isn't much fun.