Its understandable that within the context of things, that animal men are usually distinctly humanoid and that the body part interactions are quite rigidly set, as to connection joints determining posture. Being mostly just human with additional traits and a 'animal head'.
However, i am putting forward a suggestion that animal men, if they so wish with their hands free (and weapons usually sheathed) if they have the right body type and limbs can as a inherit ability (or a set of tokens to allow the ability interaction), change their stance and walk on all fours (whatever is relevant to the body type, all 5's 6's and 8's even) for a certain variety of movement and combat bonuses and penalties.
- For example take into account a alligator man, a large upright creature with a bulky profile, it its not known for its great speed, running on two legs though it is admired for its strength. Taking up a lower stance more like its natural counterpart with storage & clothing in account, it would be able to sprint on all four of its legs and swim in the water with greater speed, however making it from all directions a larger target to evade and also strike, with certain areas hidden and others exposed. With a lower and less tall profile and high speed, this same alligator person could stealthily get within range in good conditions, and ambush full charge or use its powerful jaws to latch onto a target
- Creatures with stances like these will revert to them as a viable alternative when their ability to hold items is compromised, it may also be very common for enraged creatures with stances to make use of 'wild' attacks which are buffed in this form to prefer to attack you without a weapon depending on what is most appropriate (if the attack will not penetrate tissue etc) leading to being savaged
Leading into dynamics such as animal men chasing you down rather than running at you, pouncing and biting/clawing you, pushing you onto the ground then changing stance to upright in a weapon on weapon fight, or to draw you closer into a grasp. Drawing a line between the beastial origins of some creatures and the polar opposite civilised nature of the current entity races. In many ways it can be seen as a benefit in favour of animalmen, but on the contrary being able to stay in a upright stance offers advantages also to accuracy, focus and spotting (being taller for one, head raised above the underbrush and aware of the skies), a troop of animal men blindly charging forward like beasts with great force is often combated by trained weapon and shield bearing upright soldiers to take the brunt of the attack and return the damage.
- Working in reverse, natural wild creatures with a distinctly upright stance such as bears/gorillas/yeti's etc gain bonuses to limb wrestling when in a upright state which the normal upright beings enjoy, humanoids with lower profile stances but do not walk on all fours scurry usually with the support of a arm and can grasp with one hand in this state, however with a general penalty to accuracy.
- Were beasts upon turning might also revert to this form for the purpose of faster movement and using their natural assets and intense strength
Stance climbers, 'stance fliers' (having wings retracted and out) and stance 'swimmers' all would use attributes attached to body parts in, to which the limbs would be dedicated. A whale man in their natural posture of laid out swimming through water could still strike you very clearly but probably isn't going to be able to dodge while they do it because the body part is needed, in the same vein as attacking a batman's wings that allow him to fly or cutting off a set of arms/legs.
- Extending your wings to help glide off a tall building for instance by changing posture early into the fall, and guiding yourself down in a direction with the j jump and movement configurations. Gecko people exceptionally when applying themselves would have extremely good and near unbreakable grip of surfaces.
That's as much content as i can think up of at the moment to put towards the suggestion. Additional feedback to support this suggestion would be most appreciated.