technique - How do big creative writing projects with multiple people work, preferably in the videogame industry?

I was reading some questions and answers on this site about writing for video games, when I stumbled upon this answer that mentions some things I am not familiar with.

In an ideal world, there would be a lead writer but this is not always the case.

and

In such a huge project, the writer is just a very small cog. The writer may answer to a lead writer and the writing team will answer to a director or project manager

As a programmer this sounds quite familiar. Writing code in a team is normal for me, but I am not sure how this would translate to writing.

For example I know that you normally would have coding guidelines, such as (simplified) "variable names adhere to certain principles, an example of which is that boolean values start with 'is'". There are also abstract concepts of how you want to design the overall software that are often designed by others than the ones who implement the small details. Basically everything is broken down from completely abstract requirements to manageable tasks (ideally).

How does this work in the writing industry, preferably in the field of writing for a videogame, where apparently multiple people are writing for one project?

Are there guidelines such as "We only write sentences that are no longer than 15 words for character [x] because he wouldn't use that." and "Character [y] has to use the words 'Like, totally' at least two times per paragraph." for individual writers?

And are these writers supposed to write different scenes? Or are they working in groups and each one has "his character"?

How is a "Code Review" done? Is the lead writer doing all the editing so that the final product feels like it's written by one person and there are (not as many) incongruities?

I'd imagine this to be quite a different modus operandi from other kinds of writing projects, such as writing for a TV series where you would have some guidelines on how each episode should be structured and some general character traits and at the end the character should still be basically the same as in the beginning, except for some major episodes, such as the first or last one of a season. It's also different from a novel that is normally written by one person and then edited by one other person.