#tfidw2

We are told that Nominus not only oversaw the final push against Exarchon - which happened like, 2000 years Before canon events - but also that he was the one who was in charge when Bumblebee and Cliffjumper were built - and Iacon was already rebuilt by that point, or at least mostly rebuilt from what we could see

2000 years to a species who can live up to millions, at very least, is like. Not a lot. At most a month or a year, something like that; Meaning that Sentinel could have only become a Prime at least 500 years after the War of the Threefold Spark ended, and that is if we are being generous with how quickly the Constructicon's finished Iacon and of Bumblebee and Cliffjumper's age.

So like. Sentinel, although he probably had been trained to take up the mantel of Prime by Nominus, was probably a young Prime by the time we met him

At most, he was like. A newly elected president who may not have yet fully completed a year on the job (maybe even less, enough to settle in with a new president but to still be considered a New President), because even though a lot of time passed to us for Transformers, it isn't, again, a lot comparatively to their life spans.