So, the trolls. Since we know none of them were actually born out of a mother grub, but were ectobiologically created and then landed via meteor, this means that any "descendants" are possibly not the ONLY descendants. Specially since the ancestors were legally obligated to provide genetic material. So, wouldn't this mean that, possibly, there were actually (not anymore, obvs, since they all died) "siblings" to the player trolls? Trolls with the same blood color and symbol, and ALSO descendants?

It is entirely possible, except probably to the Sufferer since he grew in secret to conceal his mutation and thus likely was never forced to fill a bucket.