to all the Posters doubting the legitimacy and using the runners prs as reference, I would point out 2 flaws with that.
1 is that obviously they could have prs which are a bit off their real Best time. maybe a race wasn't executed as well as it could have, poor weather, or the time is a bit out of Date. whatever reason there's definitely ways a runner can actually be faster than their pr suggests.
2 is that in the 4x1 the acceleration (the slowest Part of a 100) is basically "free" as all runners have the whole exchange zone of 30 meters, basically a 4x100 split doesn't really have a drive phase, it's just one long fly. This means that Guys with a comparatively poor starts but great top end speed and speed endurance do better in the 4x100 than they would in the 100. That's how I was in highschool. Totally plausible that at least some of the Ascosita kids are Specialists at finishing and this also helps the relay time be faster than the prs suggest.
My personal opinion is that it's probably a combination of both of those to some degree, and the fact that their handoffs are just really damn good.