I personally don't have DID so I don't have too much right to speak on the matter compared to other people who have DID but I've done my fair share of research but I can say there probably should be more then one alter. Alters can have certain purposes when it comes in relations with the host such as being protectors, gatekeeps, child/little alters, even fictive alters (which if I'm remembering correctly they can be based off of fictional characters), and the list goes on and on. A system can have as little as two alters to a hundred alters so keep that in mind too and the alter can depend on the type of trauma this character had to endure so context is key when choosing who they are.
Also as on little information of what people may or may not consider about alters the only thing that comes to mind at the moment is that certain alters can experience gender dysphoria, since they may identify as a male but the host body is female or vice versa. Maybe they identify as non-binary and is stuck with a body they aren't content being in. Just something to consider in mind for when you have alters of certain gender identities, of course they can dress and present themselves how they want but even then it can still be a HUGE stress in an alter's life and when they front. I had no idea this was a thing before so I just think its probably good to keep in mind.
I will say that its probably better to find real stories and people rather then just articles, every system and every experience and every trauma is different so make sure to branch out. Its good to know the ins and outs of how it works but its just like any disorder and that everyone is different and copes in different ways.
With that in mind, at the end of the day its still induced by trauma. I personally don't think its best to demonize DID but that doesn't mean its sunshine and rainbows and from what I've heard its a very chaotic experience. You have to be careful on how to portray it since especially in media its not been portrayed well.
Hopefully this helps, if you have any more questions or need clarification feel free to ask! Just remember I don't have DID so I can't speak about what the experience is like, hopefully there is someone else who can add to this with experience but thats all I got for you today!