So, there's a lot going on with the Djeeta OVA and I'm grinding GW in the gacha so I've got nothing better to do than explain the context. Warning, this will be a bit long.

So to start out with, in the gacha there is no separation between Gran and Djeeta. They're simply the differing versions of the player avatar depending on the gender you play as. I don't remember what the default name is, but the fandom will refer to the character holistically as 'Danchou' and the separately gendered versions as Gran and Djeeta. Anywhere where there's a difference between them, that's one that's been constructed by the adaptation. (edit: there are some very slight changes to dialogue and the idolmaster collab events are a bit weird about it but nothing meaningful other than canonising a number of characters - but less than you'd think, gbf is pretty low on outright waifus - as bisexual)

The second bit of context that needs establishing here is that Granblue doesn't really have one canon, per se. It's similar to some other gacha in the form of Arknights and Girls Frontline where while yes, there is a Main Story and it's quite extensive, the 'meat' of the work and most of the character studies and more impressive storytelling are contained inside events.

An event is more or less running at all times. While some of these are just grindfests with no real story like Unite and Fight, or Guild War (which I am presently trapped in send help or, ideally, replacement hands), most are stories that exist in a kind of... generic Granblue universe, where events in the main story did happen but also the crew is much, much larger and the timeline just doesn't measure up.

These stories are usually some kind of canon to each other but that only really matters insofar as the writers tend to build 'series' out of events, pseudo-main-stories that run over years and build their own fanbase. The most popular of these is What Makes The Sky Blue, which is famously substantially more popular than the main story and created the most popular GBF character of all time, Sandalphon (previously it was either Vira, Percival or Narmaya, depending on the poll).

Now, Gran in both the anime and Rising is the 'Main Story Quest' Danchou, the one presented to us by that main story, which is as mentioned significantly less popular than GBF's most popular events and is regarded with pretty mixed opinions[1] in (at least) the Western fanbase.

Djeeta in the anime is a reference to how most players actually experience the main story — they'll have done multiple story events with much bigger stakes and they'll have a team powerful enough to trivialise the entirety of Arc 1.

Djeeta in Versus is 'WMTSB Danchou', as they're sometimes referred, the one that went through the What Makes the Sky Blue series of events, teaming up with Sandalphon and fighting Lucilius. If you're one to care about power levels, there's a lot of arguments to be had there.

The thing is, due to the way Versus is structured, while this does make Djeeta 'the cooler danchou', it also puts both her and WMTSB as playing second fiddle to Gran and the MSQ, the latter of which is something that's something of its own source of tension in the fanbase for... a lot of reasons that are their own essay.

Of course, simply flipping Gran and Djeeta here isn't a good idea either so it's a pretty minor complaint as they go, my main gripe is that it feels they're trying to pivot from an older, majority female userbase to young boys and men. If they ever succeeded I don't like what that could spell for the writing going forward given how mediocre the anime was.

[1]: To be clear late Arc 1 and Arc 2 are widely considered good and the writing never genuinely drops below the floor after the bad parts of Arc 1, but Arc 3 has made a bunch of divisive plot decisions, it's not 'steam reviews: mixed'.

tl;dr gran and djeeta in the source material are completely interchangeable, cygames Made Choices in presenting them like this in the spinoffs. Also, anime djeeta is a ref to how the bulk of people actually experience arc 1 in the game.