If someone wants to do a proper answer with specifics or has corrections, they can, but I can give a rough summary for now and maybe later reread some chapters and get the specifics.
This wont be perfect timeline wise either. I assume by S series you mean the side stories which start off with the reincarnated babies, then I will go a little farther than that, to the point where they are young teenagers or so, since some details I forgot or are ambiguous on the timeline until then.
For manga readers at least, this will be full of spoilers from the light/web novel, since this is all after our spider MC leaves the dungeon.
2-4 of them
died while young and are not important to the story. It was at least 2, but up to 4. I don't recall specifically, and i believe the skill used to say they were dead might have been wrong about one or two of them, but its been a while and I don't remember nor have time to confirm right now.
2 of them
were born in one of the major kingdoms, including one of them being a prince and younger brother of the one with the hero title, and the other a boy being reborn as a girl.
Another one was
born as the next in line for the strongest swordsman
And all 3 above were sent to the same school, along with the Teacher, who
was born as an elf, the child of the leader of the elves, though I recall it was a bit more complicated than that.
born in a small village and became adventurers together after it was destroyed and everyone else killed.
One who became a major character was
born in a town as the highest ranking vampire possible, to the local Lord of the land, and our MC meets her as a baby shortly after leaving the dungeon.
Another Major character
Was born as a goblin.
The 2 above joined the MC and going further into detail why/when is heavy spoilers
Most if not all of the rest were
kidnapped by elves and raised in their village, isolated from the world. A few of them were raised elsewhere still ended up in the elves village, like one from the church I believe it was.
That is at least 20-24 of the 27 of them accounted for, but I can't recall any more right now.