It is often very difficult if not next to impossible to make the hydraulic side link exactly the size of the stationary link and still have an equal amount of tilt to each side. By installing the manually adjustable side link opposite of the hydraulic link, you then set the hydraulic link at mid stroke and then level the hitch out with the OEM adjustable link. Now you have an equal amount of tilt to each side. This only works if the design of the hydraulic link is to obtain an equal amount of tilt to each side. There are side links out there that are intended to only tilt in one direction : and if you were to adjust the OEM link to get the tilt equal with one of those hydraulic side links, then your implement would never lift up as high as it should.