Why keep the humanoid body plan?, which is the advantage of the humanoid shape? This were my principal questions when I was wondering about the features of different fictional specie, so I reached to the conclusion that the ability, as simple as it sounds, to pick up a stone from the ground and throw with force, is the main physical ability of the humanoid species known in real life therefore it is to be expected that fictional human-based species will maintain this characteristic, since the ability to attack an opponent from long distance is something that almost no species has.
Till where I found, this is principally caused by the human shoulder shape, then I thought, I just should keep this shoulder shape in my humanoid species, in other case there is no reason of why make them humanoid, but I was searching more information to support this thinking, watching some videos of baseball players and javelin throwers at the time of throwing and looks like this requires a great rotation of the torso, from the lower back to the shoulder so that this is behind the head and somewhat elevated.
So the problem is that this looks excluyent with many classic fictional species.
I don't know if my assumptions are correct but looks like these two examples with massive neck muscles to support the head hunched posture will have problems to do the kind of moves that I described, even if they have the correct shoulder shape.
So, How much I can change the humanoid body plan and still be able to perform the high speed throwing?, because this could be a delicate balance maybe i haven't even considered that a seemingly minor change just adding or removing a vertebra could change this.
Note: Several of my species can be considered humanized versions of different animal species, they just have to be biomechanically functional and the reasons of why they are humanoid at this moment are out of the question topic.