Ah that's right, it makes sense to me again. I had forgotten how I had to think of it to make sense, haha.
By moving the inner point up, you are making the LCA angle better but the tension rod angle worse. By moving the outer point down you are making your tension rod angle and LCA angle better at the same time. The tie rod angle can be fixed with spacers and heim joints, much like the spherical bearings and spacers used for the roll center.
Here is an interesting article that somewhat explains why one type of roll center isn't ideal for everyone/every car. Unfortunately they're talking about stock cars and they have completely different suspension set ups then we do:
Accelerating Performance: Roll Center Magic