Not true. See my previous post.
Sliders aren't absolute. They don't override the ratings, they just tune them evenly together.
If you put Power to 0, that doesn't mean nobody will be able to hit homeruns. The power hitters would still be power hitters in respect to other hitters because their power ratings are generally higher than the rest of the field, it will just be tougher overall.
Besides, I think the Devs have stated multiple times that the difference between the -5 and +5 scale in the sliders isn't that extreme.