At that height I doubt your tyre will be contacting the guards. Does it mainly scrub on full lock? Eg: when parking

It will most likely be the plastic inner guard liner. When I had this problem I just got out the heat gun and went over the bits the tyre was contacting to stop it. Eventually the tyres will just wear the plastic away anyway lol

If it is the guards just get some more camber dialed in but i doubt its that.

Ryan