Its actually simple...
In the first diagram the line is for the CB path which is roughly a half ball hit from anywhere along that line. The shot is the same angle at any distance on that line.
On this second diagram, the blue line indicates the line the OP is talking about moving the CB on which if is a full CB hit line. Now moving the cue ball along this path you will have different angle to make it from every distance you shoot it from.
Not sure what an ap has to do with any of this. They are two different shots from two different distances at two different angles. Just shoot to the ghost ball, pocket it, and move on to the next shot.
