One of the players in my group posed an interesting question to me earlier today; and I couldn't find a clear solution (though we did find a logical one)
How, exactly, are the limbs numbered on a synthmorph?
Anthromorphs like the Case and Steel Morph don't list any "extra limbs" in their stock Enhancements or under Morph Advantages.
Nonhumanoid synthmorphs like the Arachnoid, Reaper, Cetus and Fenrir list what appears to be their total number of limbs as "Extra Limbs" in the stock Enhancements and Morph Advantages.
So; as written: either the Case and Steel come as quadruple amputees (well, it is a Case. You get what you pay for), or being humanoid gives you four free limbs. Common sense, obviously says that it's just the authors' way of clearly stating the total number of limbs for nonhumanoid morphs. But then, you've got to wonder what Hoyden engineer thought it would be a good idea to load the egos of six soldiers into a big walking tank with no ability to manipulate the world around them during their off-hours except to kick things or club them with a gun barrel.