The following video by the Arizona Game and Fish Department discusses the use of habitat enhancement funds on the Heber Allotment, which overlaps the WHT.
The Western Watersheds map shows the arrangement.
The ranchers also benefit from mining operations, in a way you might not expect, as noted at 1:49.
As for the horses, they weren’t considered in the analysis.
The forage assigned to livestock in the allotment is not known and Western Horse Watchers has not yet discovered an equivalent to RAS for the Forest Service.
Forage density (AUMs per year per thousand acres), is a better indicator of carrying capacity than AMLs.
Western Horse Watchers Association 
In the name science, in the name of integrity & curiosity, HOW CAN ANY SELF-RESPECTING EXAMINATION OF FACTS IGNORE THE HEBER HORSES WHEN PURPORTING TO CREDIBLY ANALYSE CARRYING CAPACITY OF HEBER HABITAT?
https://www.fs.usda.gov/detail/asnf/landmanagement/resourcemanagement/?cid=stelprdb5381976