Board Thread:Warhammer 40k General Discussion/@comment-5.65.81.205-20131002091720/@comment-3258762-20131114083958

Callummacdonald79 wrote: he was engineering humans long before the primarchs, and while he ultimately disposed of the thunder warriors it set the mould for his future plans. he also created the custodies before the primarchs and it may have been more advantageous to create more of them and have them wage his crusade. yeah, without the primarchs there would be no astartes but i think emps would still have created other astartes-like supersoldiers, who wouldn't later have to choose between the emperor or their primarch. i'm just hypothesizing that without primarchs the gods would never have had such potent levers with which to alter the balance of power. The Thunder Warriors were short-lived, the time it would have taken to travel across the galaxy would be impossible for them to preform for long times.

The first Space Marines had extreme problems with gene-seed as it deteoriated quickly and thus led to tremendous failings that could only be fixed when a Primarch was discovered to renew the Gene-Seed.

The Custodes apparently take an eternity to create a single one of. They are tough, yes, but they are not immortal or invincible. It would not be prudent to create an army of Custodes.