TWO ENGINEER SHIPS CRASHED WITH DEATH DELIVERY ON BOARD

So, we have two different enigneer ships both carrying death delivering bio-weopans both crashing on two diffrent planets. We learn that Engineers create and destroy life consistently. In opening scenes, they create, in other scenes, they set out to destroy...they are playing out a GOD role here...but they are not that good at it becasue they keep dying on the front and back-ends