I think that in the movie to come there should be more good guys than bad guys. That was the way it was in the G1 cartoon. The logic of that was that the Decepticons were stronger.
Also, I dont think so much robot characters need to die. and if they do have to die, the same amount of heroes and villains should go.
The reason for that is, in my opinion, good villains are villains that you dont want them to die (you may want them to lose, but not die). you want them to continue fighting the heroes.
That is the same reason all the classic great villains are villains that we love and dont want to see go away.
A hero is as good as the villain beside him.