Descendants makes no sense?

So the main characters are the kids of villains/Disney princesses, but a lot of them lived in completely different time periods and places. Mulan for example, lived further back in time than cruella devil, yet Lonnie and Carlos are almost the same age. So none of the logic makes sense. the characters would all be living in different time periods, unless the fairy godmother used her magic to bring everyone to present day, which to me sounds like a cover up for the unlogical story. also who did Jafar have Jay with? Or did Jay just spawn in. Same with the Evil Queen. And didn’t Ursula die. So why is she present in the second movie? I HAVE SO MANY QUESTIONS! 😭