Yes, I love those ideas. So beyond that you don't have much of a clue. I think after the Komodo jock and the Kobold update, the Rhino should most certainly have an update with the Bat and the Shark. Since these characters need a little fleshing out as they are starting to fall behind a little bit in terms of content. The Rhino especially, he's been here since... Almost day 1? Wow he needs some updates. Of course you could eventually have a patron poll for what group of characters after the Komodo jock and the Kobold have an update.
Right now I can see a few group character updates.
The Rhino the Bat and the shark. Since these three are some of the least fleshed out characters and perhaps the most interesting because of their implicated dynamics.
The Admiral, the dragon and the Raven. This is mostly because I like these three characters individually and I want to see more of them. Since the Admiral just seems like an optimist who could cheer up spirits on a rainy day.
Finally there also could be the Snake Chompo and the alchemist. Since a living plushie could be an interesting storyline to pursue. Especially since the Alchemist even mentions a weird dream he had once and could be interested in it possibly being a dream or not.