It's not just FIFA and NHL friend.
EA Sports titles as a whole, since I have been playing their games (which has been since their first releases) struggles to convey difficulty. Most commonly, EAS (and really most sports games period) end up lowering one side's ability level while raising the opponents ability level.
And as you indicated, it really just gets frustrating when not only is the game doing things (most especially, combinations of moves) that really aren't humanly possible and giving you the double bird of your AI team mates running about with a bad case of the stoopids. I mean go get the ball...its in space...in front of you...nobody is around...oh but of course...retreat to your position...who wouldn't? GAH!
But this is a larger issue that we really don't get much back and forth from the devs on...how exactly do you convey "difficulty"? I'd say especially so with the FIFA community who likes their CPU vs difficulty traditionally pretty steep. Mind you, this has been through a period where EA Sports has been really guilty of something which is building and catering their game build to wam-bam 5 or 10 minute action packed arcadey style play.
Anyways, agree with you, its been this way for a while now but really the larger question is in a sports game, how exactly do you convey "difficulty" level? Tough question but if we are moving to the new messiah of game engines in Frostbite and we are getting a true ground up build of our games, maybe something we should be discussing is difficulty level and how it could be conveyed way less bs'E. I'm for way, way more realism myself. If it's in the game right?
/dos mas centavos