Suspension design is a real black art that's only understood by 3 people, and they don't agree
Seriously though, too much emphasis is placed on roll centres, they are not the be-all and end-all of suspension design, there are lots of factors to get you head around and the end result will always be a compromise. In reallity what you want to concentrate on is how the outside wheel, the one taking all the load in cornering, behaves, it's important that the wheel is upright through various angles of lean, with CAD you are able to plot all this.
Kind regards
John