Yeah, but chance creation statistic say it all. It's all in the programming, it's only a matter of exploiting it or not. Your choice.
With more chance creation, the number of times you attack instead of defending greatly increase therefore have a great impact on your chance to win. It is extremely difficult to win if your opponent attack twice as more compared to you, it's all about probability.

And the stuff I've talked above have nothing to do with real football, just how the simulator react to different positions in general.