I dont know why I need swarm missiles when they fly directly behind each other. If i can avoid one, i can avoid every other missile also, so i think it would make sense when every rocket "attacks" from another direction to make it more difficult to flee

Sandokan-

True, swarms are *launched* one behind the other, but as soon as they start tracking a target they fall out of line and begin to close in an arc. Therefore it's not exactly true that if you avoid one, you avoid all of them.