That's a tough mentality to have. The question should only come up if it's consistently happening based on the sample size. So if you hit the post 3x in a match, it doesn't mean lower shot error. It may mean it's just that match. If it happens in 5 other matches, then yeah, that's enough to change sliders.
For me, FIFA 18, and 17, are not engrossing as much due to the Frostbite engine. It doesn't accomplish the slick surface, the realistic CPU build up, from FIFA 16. It suffers the same issues of PES 18 with matches starting to feel samey. It takes a couple matches though, unlike PES. PES, for me, takes a couple minutes into the match. The second I have all this space on the flank and through the middle, it's nap time.
Oh well, I'm still playing FIFA 18 and 16. I want to get the CPU to play more like they did in 16, but that may be a difficult task as they are engineered to go forward as quick as possible.