As I was just playing my game, I thought about adding another element to the game, "missile health" and "weapon damage".
By doing this I can assure that there is an advantage to using different ammo types, for example;
A missile is going to spawn with random health between 1 and 2, the "Blaster" will do 1 damage, meaning some will take two shots, whereas the dual shot will do 2 damage ensuring all of them will be one hit kills.