When guardians target players, they lock onto a single part and concentrate fire on it. When facing multiple machine gun guardians it can vaporize parts instantly and there is no way to avoid it because projectiles seek their targets with unlimited range.

Make guardians target parts at random each time they fire (excluding the pilot pod), and make projectiles travel in a straight line with a limited range/lifetime until they hit something so players can armor themselves instead of having their critical parts pelted by a constant line (yes, a line) of enemy projectiles.