As I mentioned earlier, we had a breakthrough tonight. However, it's not slider related, it's primarily the base of the gameplay related.
The working theory here is that EA coded the game under a squad/team sheet with default instructions set up. However, when they started pushing updates, or even releasing the game, they modified the default instructions. As a result, the game is coded and out of sync. This is why we see these terrible defensive issues:
https://twitch.tv/videos/485359952
https://twitch.tv/videos/485359951
https://twitch.tv/videos/485359953
As a result of these findings, we approached it similar to how I have approached PES in the past. Basically, using a rubberband type of logic where what I set for the user, the CPU responds. Instead of sliders, it is the player instructions. So, at the start of the match, I paused the game, went into my player instructions and click "X" to Reset All Players to Default. Yes, this does mean the player instructions revert to default, and custom instructions are no longer applicable. This is a workaround, and by no means, hopefully, a permanent solution.
Once this is done for the User side, simply play the game. Try to burst past the CPU and recreate the videos above. It will be much more difficult. You may need to experience this on Legendary or Ultimate vs using World Class or below because lower difficulties can have certain exploits, etc. At the time of this post, I spent more time using Legendary.
One additional, and highly recommended, enhancement to this is one in which the user would need to have a second controller (console) or keyboard (PC), so the same can be done in the match for the CPU side. Simply switch sides, then navigate to the player instructions > "Reset All Players to Default". Once done, go back to switch sides back to no team selected.
That's it. That is the big find. It is proven on the twitch stream tonight, and has been exhausted to isolate certain triggers that may, or may not, be effective. I will say when both the User and CPU are Reset...it is by far one of the most fun experiences I've had with default FIFA since the prepatch beta. You will be able to tell instantly of the better lines, the more resistance, the entire environment of play rises to another level.