Different struts can have different damping capabilities. If one side responds differently to the other it's not too big a leap to antcipate an impact on the geometry of the front assembly at run time under load. That is when tires wear. not when the car is stationery. It's not simply a matter of component length and adjustment. length. If you were to change the FCABS using two different types of rubber you would expect it to impact the steering under load even if the geometry was perfect at rest. That's why it is always advisable to change these things in pairs.While I don't disagree that having one oddball strut isn't good, how exactly does a bad strut "change camber"? Camber is simple geometry and unless a strut is shaped like a banana or something the camber is going to be unaffected one strut to the next.