Having no functional stance parts, I would guess. Although that's also true of snakes, but snakes don't fall over.
Basically I am trying to change the size of black mamba men to be the same size as dwarves. I looked in the creature_tropical_new.txt and noticed there was only body size parameters under the black mamba itself, not the black mamba man or large black mamba. Then i remembered that it works on a conversion table. I might sound stupid but i tried to do some math with the sizes of animals and such to see what the tables multiply by, but gave up because I want to change the black mamba man size itself without affecting the black mambas size.
bringing this up again, would really like to know
Could try adding BODY_SIZE:12:0:70000] to them after the creature variations have been applied.
Is there a way to actually tell if the tissue modifications I made are actually working?
You'd only know outright if you changed something that would be blatantly obvious, such as name strings of the tissue/meat when the animal is injured/butchered, or something equally visible. If it's just a change to the numbers, like vascular or healing rate, you'll want to compare the change between two identical creatures; one with the changes and one without. Set up a dozen of each and whack them all with a stick/dagger and see if you can spot the difference between the two.