"5 constant hits will stun the targeted player" that will literally buff other champs, not only towers.
Heavy overloaded champs with stuns & slows will just be undiveable "Nasus", "Leona", "Thresh". On a nother note if the tower stuns the player, that means the tower gets to hit the player another sixth shot.
This is not just a slight thing that can through, this can change the whole game standards.