I had a cursed idea, and you’re all going to suffer with me. :3
So - what if Cybertronians are like ants?
The All-Spark is a queen. It does not require a male to create new sparks: all of the sparks that come from it, are female. Most of them are infertile females, divided into two castes: warriors and workers. (Fun fact about ants: most ants can only produce males from unfertilized eggs, but there are approx. 16 or so species that can also produce females that way).
A Prime is an immature All-Spark, and the All-Spark will only produce one at a time. After reaching a specific point in time, the All-Spark will also produce a specialized warrior: a titan, which the Prime can then board along with a court of workers and warriors to start a new colony.
Only after this happens, will a new Prime be created.
This cycle was broken up by the creation of the Matrix: an artifact that can prevent a Prime from maturing. I’m not yet decided why exactly they’d do it? Could be that one of the Primes didn’t feel like they can leave Cybertron at the point where they knew they’d have to soon, because there was a civil war going on?
Alternatively, perhaps they felt that they were wrong to just go off and colonize worlds?
In any case, this Prime is dead, but their spark is still contained in the Matrix, which has been carried by several workers and warriors. Their sparks have also probably been absorbed at their deaths by the Matrix.
And then one day Optimus Prime leave Cybertron on the Ark and disappears for millions of years. The All-Spark goes “FUCKING FINALLY! BITCH TOOK HER SWEET TIME!” and promptly creates Hot Rod.
To add to the fun: Unicron is one of the off-spring Primes that had the bad luck of maturing on a resource-poor world, and failed to create a proper colony. So now he seeks vengeance on its parent All-Spark on Cybertron and chomps on planets along the way.
