Some Advice Would Be Nice (Gmod Player Model Issue) - Developers

Does anyone know what is causing this issue? For the last 5 days I have spent hours and hours learning, googling, watching videos, reading forum posts and have gone from knowing nothing about Crowbar to what I have got now. I took the XPS file, put it into Blender, all of the weight painting was already done as was the rigging, all I needed to do was create a phy and anims for it and rename the bones to Valvebipeds, after that I set up the QC file, spent hours and hours viewing and learning from other QC files to figure out what I needed to do, but obviously somewhere along the way I have missed something, and after hours of looking for an answer I have hit a brick wall so I have had to ask you fine people for help. As you can see in the background, the ragdoll works perfectly fine, but when it comes to the player model, its a monster, a number of things appear to be stretched and deformed. I can only imagine this is an issue with the QC file? I have gone over the model again and again, the weight painting appears to be fine, the bones are all very similar to a number of other models I have put into Blender to compare with, I have even added bones and removed others to see if that would make a difference, it didnt. I messed around with $definebone because originally I thought that was the issue, it doesnt appear to be considering the image was taken with no $definebone in the QC. When looking at the viewer in Crowbar the model appears to be fine, Physics and Bones are all in the correct place and move as intended. If I remove the "$includemodel" lines from the QC the model returns to a Tpose but looks fine, but if I put them back in I get this. So, is this an issue with the QC or have I fucked something in Blender? I can provide images if need be, I just didnt want to spam the original post with 4million images. Thank you in advance, you are an extremely handsome individual. https://files.facepunch.com/forum/upload/346110/f05765d5-2ba0-413e-8e4c-32d518c97390/Monster.png

Its not as simple as renaming bones. You need to rig the model to the valve biped skeleton in order for the animations to work properly. All the bone positions and rotations must be the way they are on the valve biped skeleton.

https://files.facepunch.com/forum/upload/346110/749cc87a-6077-4c06-b707-3fe46c8a892b/Feet.png Using the feet as an example (My model is on the left, Valve biped skeleton on the right). I see what you mean, so my issue is that I need to rotate the bones to match the Valve Biped? But you mentioned position, just to be clear, the Tpose itself doesnt need to be the exact same right? I have seen a number of models with the lowered arm Tpose, but I have also seen it work with models in the straight arm Tpose, if that makes sense. And thank you for the reply, its appreciated.

After messing around with the bones, positioning them and rerigging them to the mesh, I am still having the same issue, again perhaps I am missing something? Just to preface all of this, I am well aware that I should probably just rip a skeleton from another model and use that, however out of my own curiosity and determination, I am looking for a way to be able to turn the existing skeleton, which has all been pre weight painted and rigged up perfectly, into a working model, this way if in the future I want to do this again, which I do, I have more knowledge about the process and the limitations of what is possible.

As it turns out, I am an idiot. Thank you Rubat for your reply, after that reply I went over my model again and again referencing it to another model, everything was the same apart from one thing, the Roll, so after adjusting that to that of a Valvebiped, the model is now working perfectly fine, it still needs some touch ups here and there, but this issue has now been fixed, so thank you Rubat for the reply.