This isn't a White Sox thing, this is 100% normal. As an athlete, being asked to practice as at 80 or 90% is a normal thing. Injury talk is the same way because there is no scientific way to exactly measure injury recovery. As with a lot of injuries there are levels of activities you can undertake so as to aid in your recovery. If you tear a Hamstring you don't lie completely immobile from the hips down until you fully heal. You start doing little things like short walks right after surgery to keep your muscles active. Even Tommy John guys are throwing before they are 100%.
You are hung up entirely too deep on the percentages for no good reason.