Funnily enough I've started killing time during lockdown by watching youtube videos about tanks. You need to trade off armour against weight and manueverability! No good if you can't get over bridges without them collapsing! Also - watch out for that German tendency to overengineer everything! (Not sure what the analogy is with PPE for pandemics, but there must be one in there somewhere?).Certainly an inadequate sheet metal shield would still be able to deflect some shots that come at an angle. Even with straight-on shots, it would slow the projectile and reduce its body penetration power somewhat.