I think the issue is them not tracking back, the ai shouldn't defend for you but it also shouldn't do nothing, there has to be a decent balance. If the ball gets passed between cdm's and cb's, you either have to control the cb and watch as your cdm's refuse to track runners, or you have to leave the ai CB to defend for you while you bring back the cdm (which usually leads to the CB getting murdered by skill moves and a goal).
That said I'd much prefer this to the last few Fifa's and its an enjoyable game, could even be quite good if all the old bullshit wasn't there. Things like tackles still falling back to the attacker, wrong pass selection etc... are all still there in droves, not to mention running fake shots allowing players to phase through defenders.