Oh gosh this might be a bit tough, but I’ll do my best!

Well… to start out, while not fankids, the OC/Legendary parent ships of Yves/Alexandrine and Yulia/Evgeny both draw intentional influence from Tangled. Yves has some Rapunzel elements in that he’s a long-lost prince on a quest to return to his kingdom without knowing his true identity. Evgeny was intentionally designed to be a bit of a Eugene expy, from his (former) occupation as a thief, to his romance with a princess, and just his name.

As for fankids though:
Sage & Celeste would make a fine Robin Hood & Maid Marian.
Luna & Nerissa would be cute as Snow White & Prince Ferdinand, or as Princess Aurora & Prince Philip.
Cypress & Apollon could work as Tarzan & Jane (in an AU where Cypress was raised by dragons until adulthood and not just until he was 8.)
Ceres & Callisto would make a pretty darn adorable Rapunzel & Eugene for the fankids (they could also work in some…. Russian version of the Aladdin story with Callisto as the titular hero and Ceres as the princess.)
Levi & Rhys are Ariel and Eric. They’ve probably dressed up as these characters before. They know what they’re about. Levi is the handsome merman and Rhys is his charming musical prince.
Draco & Addie could be an interesting Beast/Prince Adam and Belle, since Draco’s character arc involves him confronting his anger issues and part of the reason he ends up dating and marrying Addie is the support she gave him during that difficult period of his life.
Yvon & Aurélie could be cute as Kristoff & Anna.
Mindy would make an excellent Meg, but Maddie doesn’t really fit Hercules that much.

Honestly, I think for a lot of these I just can’t quite pick a Disney couple that matches well in terms of dynamics and story elements with the various fankid ships, while I do actually have plenty of fankid ships that sound like they ought to be Disney couples (like Elias and Margot…. a shy prince and an outgoing, dragon-obsessed girl.) I’m also not familiar with too many Disney couples, having only seen most Disney movies once, and probably a long time ago to boot. I’m happy to hear others’ opinions on this matter though, or if you have a fankid ship you’d like to know more about.