I'm playing as Barca and can field a whole XI of 80+ players and it's crazy hard. The AI don't give you any time on the ball, and at the same time it's hard as hell to get it off them. Have to rely on a couple of moments of magic from Messi or Neymar to even score. I've only ever dominated a team once, and even that game ended 0-0 . Good thing about that is that I've been playing around with tactics more than I ever did to try to find a winning formula.
Last year I was able to sign Zidane, Scholes, Ronaldo and possibly Maradonna in my first window as Barca, now my scout is recommending Hutton I swear I'm not making this up