Melbourne have had issues in the past with their stallions being increasingly aggressive towards their Giraffes. Despite their towering size, Giraffes are surprisingly rather cowardly!
Imo White Rhinos are an easy going species. Indians can be a little more intolerant of other species, and Black Rhinos are very territorial, and so are very rarely kept in mixed species exhibits.
Auckland Zoo currently have a herd of zebra mares in their integrated Savannah, which is a sensible move imo given they’re breeding their giraffe. Giraffe calves are most at risk from zebra stallions.
Hamilton Zoo (who have adult bachelor bulls) have had no issues from their zebra stallions in recent years. It therefore makes sense that they’re bred at Hamilton, with Auckland holding mares.
Wellington Zoo have always housed their giraffe and zebra separately, with zebra no longer in their collection. Since their last l zebras were mares, I believe this was a relic of the era when zoos held species seperate rather than a consequence of integration issues. Auckland similarly held zebra and giraffe seperate prior to the opening of Pridelands in 1997.