Law 1.
Demoknight counters sniper with the condition that theyre in the same ground.
Law 2.
Medic's weakness is too great unlike the others that it cant be S tier.
Law 3.
Spy's fact of backstab is too great for F tier.
Law 3.5.
Soldier is better than demoman.
Law 4.
Medic, Spy, Engineer, Scout...