Interestingly, at the Calgary Zoo, their females have been some of the worst pluckers I've ever seen. Every single one of their females (numbering 5-6 for the past 10+ years) plucked to some degree, with only one maintaining the majority of her hair, and at least two plucking so bad they were almost entirely naked.
Their original silverback passed away in 2016, and between then and late 2019, the troop was without any males. During this time, some of the pluckers did reduce the degree of plucking, but not by any tremendous amount.
The big difference started in September of 2019. This was when their new silverback, a very easy going younger male, was introduced. Far forward to 2021, and some of their females are virtually unrecognizable, in the best way! All of the females have noticeably reduced plucking, to the point where only one still has noticeable bald patches (their worst plucker, I wouldn't be surprised if she has some degree of follicle damage and will never fully hair out again. But even she has a noticeable amount of more hair). All the other females are now fully coated, and look like new individuals!
So in this situation, the main factor apparently was the male presiding over the troop.