Hey Mendozza.
You could and can easily implement a game controlling mechanism under the hood, and no, all people playing don't have to "experience the limitations at the same level", that makes no sense. You could easily code a system where the game takes to account, say, the money you've paid, the time you've played, or whatever statistics and calculate a probability. If the opposing player would excel in either category, or vice versa fail to meet the hidden statistical quota, you could easily manipulate the game mechanics (increase mistakes, nerf statistics in situations, whatever really). Many people are convinced this happens, and EA has to pull quite a few rabbits out of their hat for people to think otherwise. My guess is a need for ad/"pay for play"-profit and thus, keeping players engaged on the long run, evening out the "playing field", by force if need be.
I'm pretty sure EA has a system to keep the money coming in, and it would be stupid if they didn't do that. Almost every content creator and platform does this, no matter if they openly admit this, or only in court.
This is definitely what I feel happens. And I'm not always on the losing side, sometimes the table is turned and I occasionally play against opponents that cannot get past my superman CB's despite them having cards of similar quality. I don't even have to play, I know they'll fail to score in any case, just the same way I do when the table is turned.
I haven't noticed any lag you mentioned, this has got nothing to do with that. I am an old gamer, so I would prolly notice a lag and be able to compensate these sort of issues and score...
... and I don't think lag explains my strikers all of a sudden passing a ball backwards. This never happens in any other setting than H2H games.