It was messier in the comics because Wanda already had a pretty convoluted history with tons of retcons. MCU Wanda doesn't have that same baggage, so it would be a lot easier to establish some of those concepts there. And I'm just suggesting Robinson because of the rumors that Tom King's run was a inspiration. Both books were published at the same time and both had Agatha Harkness, so I can see the showmakers seeing this as an opportunity to interconnect them in the MCU in some way. Which is not to say they weren't inspired by some older books as well. I think if done well, they can mix up a lot of certain elements and make it work.
After seeing the poster, I'm convinced the twins are gonna be humans. Or at least human-looking twins. It doesn't make a lot of sense for them to use this ''traditional 50s family'' aesthetic and then add two synthezoids as their children. So IF they have any kids, I'm betting it will be the classic William/Thomas OR they're gonna make Vin/Viv looking like humans. Either way, I'm like 90% convinced that the kids in this wouldn't be real anyway.