I’m trying to think of a reason, in a continuity soup au, why vosians would have 2 or more kids as the norm. I think I might make it a hot spot mutation that was passed down the generations? And the city’s hot spots shut down and couldn’t reactivate so hatchlings? Maybe timed so that vosians go in heat the same time cybertron prepares to create new sparks for the hot spots. I don’t know what this would mean with a barren cybertron, still thinking.
In biology, multiple offspring usually point toward a high mortality rate; it evens the odds that there will be survivors to pass on the genetic line. I think your strongest reasoning for Seekers to have 2 or more at a time lies there. But, I would also say there's a strong case for ALL Cybertronians having that quirk, not just Seekers.
But, if you do say this is unique to Seekers, the consequences will mean a higher population of Seekers. Do you plan on Cybertron being majority flight frames? If you don't, then what deathly thing would affect only Seekers, and continue to affect them in more prosperous times, when health standards would be higher?
I would say Seekers are naturally predisposed to a LITANTY of chronic diseases that are costly to fix. Code that's broken from the time they're conceived, severe energy inefficiency, a self-repair system that won't come online, nanites attacking their own body, a malfunctioning transformation cog that rips them up when they attempt to transform; you could get really creative with it. And sad. It would be a very sad thing to do, but it's what immediately comes to my mind.
You could also say Vos is a hellscape. I know the typical fandom interpretation is this paradise in the sky, but you could make the place naturally deadly. This would make multiple offspring mandatory for them to survive as a people here.
