ok i don't know if you understand this ^^ but here is the way you will put 1 object with 4 frames or 4 animation but all has same name like (enemy1,...)
so this object will have boolean variable and put a global variable = 1 so now event will be like this :
event1:
condition: system :compare two value --> global = enemyobject.frame
action: set boolean = true
event2:
condition1:player colision with enemyobject
condition2:system: compare two value --> enemyobject frame = global
condition3:enemyobject is boolean
action1: enemyobject destroy
action2: system add 1 to global
event3 :
condition1:system : compare two value --> enemyobject.count = 0
action: go next layout