The difference between players should be in terms of "accuracy when hitting a wrong pass": if you managed to play a perfect pass either with Pirlo or Kalambay, it should be perfect ingame.
If you play a near-perfect pass with Pirlo (on manual), it should be near-perfect also ingame while if you played it with Kalambay it should be a little off, surely not as accurate as Pirlo's one.
Or should 67 stat give you completely unfiltered outcomes, and then higher stats start giving your assistance?
MANUAL
The issue with this:
I think this only works on "direct pass to a teammate" because the CPU will know/predict who's your intended target(depending on your stick direction and power).
How about passing into a space or through-balls? How will the CPU know your intended target(space)?
The CPU only knows your input, it doesn't know your intentions.
How will the CPU know what to correct(based on stats) if it doesn't know if you made a mistake?
Should 99 stat give you a completely unfiltered outcomes (aka, your own input, nothing else). And then lower stats start impairing your inputs little by little?
I think it's good idea. On easy types of passes, anyone can have a chance to make the pass 100% accurate(based on you input). When attempting harder passes(longer range, out off balanced, one-touch, no look, weak foot, etc), there's a less chance the pass will go to your intended target(space,teammates) when using a weak passer.
That way, you're not going to attempt amazing passes with weak passers.
ASSISTED
Why not make only 1 pass assist that is, based on stats and situation?
We can choose the target/teammates based on our direction and power. We can also choose the type of pass(ground pass direct to a player, lob pass direct to a player, ground through-ball, lob through-ball,etc).
The computer decides how accurate/consistent the pass, based on stats and situation. I can't remember it anymore but I think PES6(and older) is something like this. I never player pes2008 - pes2014 so I'm not sure.
Problem: Less dependent on player's(us gamers) skills.
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Damn!
Pass stats and input skills are hard to implement in any PA's currently.
But I think,
it's easier to implement passing stats to a CPU controlled team. CPU team doesn't need to have a PA, it should only need stats. I think the CPU should stop controlling the team with an imaginary gamepad. I think, it should control the team based on stats and situations.