I’ve read that a shaped charge’s armor piercing jet of plasma has a fairly long reach. A direct hit with the plasma spear directed toward the center of the vehicle would probably still pierce the vehicle. However, a cage like that might provide protection from a glancing blow, where the plasma jet is not directed toward the center of mass - like, instead of getting a hole through the corner of the roof, the jet misses entirely.
I’ve read that a shaped charge’s armor piercing jet of plasma has a fairly long reach. A direct hit with the plasma spear directed toward the center of the vehicle would probably still pierce the vehicle. However, a cage like that might provide protection from a glancing blow, where the plasma jet is not directed toward the center of mass - like, instead of getting a hole through the corner of the roof, the jet misses entirely.