Depends on what It's really meant to be tuned for
I've done it twice, both groups were above average of 850 and we had no problems
But of course that begs the question, who is Kara aimed at?
I feel like some of the earlier bosses are overtuned for what they drop.
This would never be a problem for myself, but I can definitely see more casual players getting stuck and struggling with Kara without outgearing it.
Moroes and Curator in particular, the DPS and healing requirements just feel way in excess of what they should be for bosses that drop 855 gear.
Maiden of Virtue and Attumen are also quite difficult for what they drop but they're also optional (and attumen drops a mount) so I think It's fine that they're harder.
Later bosses are tuned fine for what they drop, in fact arguably undertuned.