Could people domesticate baboons or mandrills, specifically for usage as pack of draft animals? I am aware that they are not quite that big, but could we selectively breed them to such size and capability across millennia as we have done with wolves or such? I believe that the potential is there, as other monkey species such as rhesus macaques have shown tolerance of humans and human surroundings (though they are typically regarded as pests in such areas). Could it be possible or are baboons and/or mandrills too aggressive to be domesticated?
EDIT: I feel I should clarify the circumstances in which they would be domesticated. The society that is in place at the time domestication would occur would be pastoral nomads, herding grazing animals across desert and dry steppe. As they settled river beds, I am unsure if they would keep the primates, as their previous purpose as pack animals/herd guards would be diminished. That is, if they are domesticated in the first place.