Most animal people in Dwarf Fortress are created from the animal person variation thing that converts the feral creature into a animal person. In the process of this, even though almost all animal people are given the humanoid layout, a good chunk of them (more then half?) lack the Humanoid_Joints flag that gives them wrists, elbows, knees, etc. that can be damaged in combat or locked and broken via wrestling.
I believe this is an oversight, as the Rodent-Man and Amphibian-Man (two animal people who were "created from the ground up") have humanoid_joints, making them valid wrestling targets. However, the Rat-Man and Green Tree Frog man do not have such tag, making their joints impossible to wrestle.
Incidentally, the Bat-Man still has humanoid joints added onto his raws even though he was an OG animal-man who later had his raws converted to use the creature variation system. (But he had humanoid joints back then, too)
I'm proposing almost all animal people, if they don't have nobones, and have a humanoid layout, be given humanoid_joints. Animals with digitgrade legs turned into animal men, might be a bit iffy (i.e. their legs look different from a humans) but Satyrs and Foul Blendecs have visibly different leg layouts yet still have humanoid knees and ankles, so I think Humanoid_Hoof can be included for adding humanoid joints to.
I'm not sure on insect-men such as ant-men however.
EDIT: My concern is with insect-men, don't endoskeletons have sever-on-break or something? Just worried it might lead to a lot of snapped-off arms and legs if they get humanoid joints, to an excessive amount.