Wow, crazy that I had such a different experience. Wondering now if it was a fluke, but I usually struggle to beat World Class, and this time I played so well that I checked the settings afterwards to make sure I hadn't changed it to Pro somehow.
The passing is more responsive, which seemed to allow me to beat their pressure more often than not, and they just weren't passing the ball as precisely as usual. I think I won possession like 60/40 and almost doubled their shot attempts, although that's pretty realistic for Arsenal vs Middlesbrough. Dying to play more, this game has got its hooks in me now.