I imagine Cassandra's overall view is going to depend a lot on the story Varric told her. She wants to bring an end to the war, no doubt, but how she wants to do that and on what terms will likely be very much colored by Hawke's actions.
Viveinne's position is clear; she wants a return to the status quo because the status quo is what made her powerful. She wants a return to normalcy for, apparently, purely selfish reasons.
Going off of that, I'm given to imagine that Solas will support the rebellion for primarily selfless reasons; family, friends, the suffering of Joe Mage Public in general.
From a purely physical perspective, literally everything about Solas is the polar opposite of Viveinne. He's a skinny, lanky, pale elf who dresses in rags, she's a curvaceous, dark skinned human who dresses in horribly impractical finery. I have to assume that this is a visual cue that these two are going to be diametrically opposed on everything.
Cassandra's more of a wild card in that trio; I name-dropped her because out of the known and likely companions she's the one who has a stake and interest in the mage-templar conflict, which, whatever her view ends up being, will be the one to tie into the conflict between Viv and Sol, as I imagine it.
Or I could be completely off base and they'll be a whacky odd couple that'll star in Thedas' first sitcom.