Many years fans imagined their own version of Balto 4. Some imagined prequel about Balto's parents, some imagined adventures of other Balto's and Jenna's pups, or love story between Balto's pup and Steele's pup, and how their love stops the hatred between their parents, or the sequel of Aleu's adventures with exploration of those Inui and Native American myths and spirits and so on. 

The original film's crew never planned to make any sequels, Balto-1 was stand-alone and concluded story (although, Cliff Ruby and Elana Lesser, who wrote the first version of the script of Balto-1, were aired for work on Balto-3). But what about the crew, which worked on Balto-2 and Balto-3? Well, they had some ideas. 

Here's the vision of Dev Ross, the writer of Balto-2:

" I would take up in the wild with Aleu. Most likely, I would have her return to her father, because she needed help. Perhaps, because of enviromental issues or that her pack had been captured or run off by humans. I was hoping to do more with [Aniu] in the film, but I wasn’t hired to do another."

Obviously, Dev's movie would expanded and explored not only Aleu's journey with the pack on the new unknown territories, on the new unpredictable land with new danger (humans, other antagonistic animals or forces of nature), and how Balto helps her, we'd obviously learn more about the wolf culture, but also the supernatural elements (spirits and their nature), which had some vague answers in the sequel, but planned to be developed and explained more in the new film and now are mentioned in interview. I think, the series in TLG (The Lion Guard) style and format could fit for her story perfectly. 

For example, how Aniu was mortal grey wolf, who loved her pups and family (pack), and how after death (in ancient times obviously) and joining in with the Great Spirit (and becoming a part of this Guardian Spirit) she became the white wolf and now is the Great Mother of all wolves, who symbolizes the call of the wild and helps to find true self. This Great Guardian Spirit was in the cave with Muru, as well as how wolves bow to Aniu as to the goddess on the top of mountain (here's concept art of this sequence — the Great Spirit is in the centre, while all animals spirits surround him/her/it, and only Aniu has traits of the deity, i.e. more than just guide spirit).

 Maybe we'd learn more about this character also.

And here's the vision of Phil Weinstein, the director of Balto-2 and Balto-3:

"As far as what I’d like to see, I really like Steele from the original, so I’d like to see something with him. And I thought Aleu was a great character; I’d love to see her come back and help her father in some way. And maybe there’s even some great revenge thing with Steele, and Aleu comes back to save her dad. Or something along those lines. And that’s personally what I’d like to see, if I were in charge of handling the story. And I’d love to tie up all the loose ends, especially between the first two stories."

Here he added a bit more:

"What I really want to see is a Balto 4, Steele returns, out for revenge on Balto for ruining him, and Aleu returns to the rescue. There is something about "A daughter returns to save her father." There is something about the archetype - to me rings true. So I don't know what happened to her, but I would love to see her come back. She saves her dad, but know the dynamic is changed, because Kodi has become the Alpha, and now the sister could potentially threaten that relationship. All of those pieces seem like a good launching point for a fourth movie."

Here we see some ideas for the story, its core, but there is a lot of aspects, which have to be normally explained and have to work. Yes, there's some danger from Steele (who waited three years for revenge, I guess) and potential for intimidating villain and for awesome final battle between Balto and Steele on the mountain (I hope, not only me wanted this in the original film? in the novel Balto fought Steele in the medicine fight scene, so Steele felt fear). However, it's unknown, how Steele would planned his revenge. Who'd be his henchmens, if all dogs of Nome know about his evil nature now? Niju? Very unlikely. And if Balto was in danger, so Aleu (where Kodi, Jenna, other pups and friends?) ran to rescue him, it really needs for Steele to have some allies. 

So, that's what people, who worked on Balto 2 and 3, had in ideas for the story in Balto-4. Both have a great potential, so maybe someday we will see this.