I feel like we should see Sabine before we see Ezra to keep the story in the right order. She'd be a good way to introduce the connection between Mandalore, Thrawn, and the missing Jedi much of the audience might not know about.

Why not just have everyone?

Sabine mainly cause of what LeKit said.

Sabine being a fellow mandalorian and a former owner of the darksaber to boot would make the most sense.

Sabine! I'd love to see her interact with Din. And, maybe even change her mind about leading Mandalore?

1. Hera, could be a replacement for cara dune, which I would definitely not be opposed to 👀

2. Sabine, an episode or two to tie everything together would be nice, but I’d honestly rather keep her to the Ahsoka series

3. Chopper, I think it would just be fun if he just tagged along for the ride as Hera’s bestie

4. Ezra, like Sabine, I’d rather keep him in Ahsoka

5. Zeb…look, you’re great…but you just wouldn’t fit into the story I’m so sorry

maybe in Ahsoka

Since it seems likely that Sabine and Ezra already appear in "Ahsoka", my vote goes to Hera (though in this case, Chopper would probably be included, so it's basically a two in one-package). Single mum meets single dad.

However, it would also be nice to see the other characters again

It depends on the story. If Ahsoka's going to be in it, Sabine. If they're bringing in the New Republic, Hera. Zeb, Ezra, and Chopper don't really fit. I'd honestly rather they keep all of them out of S3, maybe bring them into S4 after Ahsoka's out

I would love to see Sabine Wren interact with The Mandalorian

None of them, to be honest.