Instant Center and Instant Axis

The one with the shorter swing arm will experience higher variation as compared to the one with longer arms. This is because, with the increase in swing arm length (the radius of wheel travel increases), thus the distance(arc length) traveled by the arms will decrease. Or in other words, camber gain is inversely proportional to the swing arm length. Hence, lesser swing arm length will have greater camber gain, leading to greater variation.