Giselle a good option? She is a no one, dont have any poilitical support, she is exactly what the Chantry doesnt need.
Giselle is the best choice from a narrative standpoint, because honestly... what was the point of introducing her if all she's going to do is sing a corny song and tend to a garden? She's supposed to be a pillar of support for the Inquisition, and she can and should be a pillar of support for all of Thedas.
She has the backing of the Inquisition, a political organization with the backing of Ferelden, Orlais, and potentially Starkhaven. An organization that has a bunch of smaller organizations tied to it.
And besides, one of the previous Divines was a commoner, not even within the Chantry hierarchy until her ascent (Divine Galatea). So if someone that poor and considered a nobody was elected to the role, then I see no reason why a Mother who faced the Mage-Templar conflict head on to tend to the wounded and is a part of the Inquisition wouldn't be able to either.
And to me Vivienne will always will be the best Divine.
Vivienne as Divine is a bit of narrative trash to me, not because of her (I actually adore her character, though I think she was treated as a narrative prop by the devs) but because of the contradictory nature the story gives you. The game tells you that you can't be Divine because you're a mage, yet hands it to Vivienne (yeah yeah, her reign has a bit of unrest, the point is the devs want to be wishy-washy).
Personally, I'm of the mind that neither Viv nor the Inq. should've been considered, the former for being a Mage and the latter for potentially being non-human and/or a mage, never mind the fact that the Divine having control of the Inquisition could lead to a theological dictatorship.
Never mind how I'm baffled how the Grand Clerics would've rallied behind a mage in the first place, when many of these same people have been so eager to call the Inquisition troublemakers at best. regardless of how some turn towards Leliana/Cass and will be amenable to the Inquisition, others are still not going to go along with the Inquisition, as Leliana's quest showed (and that doesn't need her to be Divine. It happens regardless)
The College of Clerics must be unanimous in their vote, yet they somehow go "Yeah sure, Vivienne as Divine" only to then turn around and go "WAIT A GOSH DANG DIDDLY DARN MINUTE" and act all surprised that they voted in Vivienne? Vivienne, the First Enchanter of Montsimmard's Circle, once advisor to Empress Celene on arcane matters, who was given the open support of the Inquisition? Who has been seen using magic openly?
Christ Almighty....
If anything, Vivienne should've ascended to Grand Enchanter in a reformed institution where she can properly flex her political muscles without fear of reprisal down the line, and if we believe Giselle is too... wrong for the task then this is even more reason. Because the GE advises the Divine and Vivienne could see to it that the Circles run efficiently and effectively as the power behind the Sunburst Throne. None of the blowback could go back to her, there's less potential for disastrous ruin after she's dead, etc.
And if we're to break the rules for anything Vivienne could get from a writing standpoint, then give her the power for Orlais. Let her become Empress. At least that doesn't have as much potential for future blowback (though I like my GE idea more. This Empress idea isn't even mine tbh, it's something I've seen other people post I think).
but Leliana and Cassandra have one too
Leliana's I expected to fracture.
The point I'm trying to make is that Vivienne as Divine is rife with problems, both from a realistic standpoint of what happens within Thedas where she will be under constant scrutiny, to how things will happen after she is dead, and from a narrative standpoint where the devs only inserted it to make a decision seem to have impact while simultaneously ignoring the very reason they gave you for why you can't be named Divine.
Moreover, a mage divine having such close ties to the Inquisition is bound to not be looked upon favorably, where if Vivienne's problems disappear and the Inquisition is present it will be seen as a bit of back-scratching. Hundreds of years of anti-mage/magic sentiment will not just go away no matter what she does. So long as she exists