Chain Of Command

We needed the Virus to make sure the Enhanced Troops didn't turn on us.

We needed the Enhanced Troops to make sure we could still fight through Gravity Bombardment.

We needed Gravity Bombardment to make sure we could prevent Grey Goo from spreading.

We needed Grey Goo to make sure we could take out Conventional Troops while keeping infrastructure intact.

We needed Conventional Troops to make sure we were Feared and Respected.

We needed to be Feared and Respected to make sure we weren't attacked by our enemies.

We needed to attack our enemies because they might need to first.