The onocentaur is a mythological creature that is, contrary to its name, not truly a centaur, but instead has become a quadruped
They have a humanoid upper body, with arms and hands, and a donkey-like lower body, with hooved legs. They are overall roughly donkey sized
They are facultative bipeds; they mostly move about on their hands and hooves, but can use their arms/hands to grab things and manipulate objects. Their mouth and dentition is humanoid. They have humanoid minds, but are not as intelligent, and far less inventive
This creature seems quite paradoxical: The equine hooves are adapted for wide, flat lands, whereas human arms, when considered as legs, seem to only be useful amongst branches and vines
Given this, is there any environment/niche that this onocentaur could survive in?