Textures contrasting each other on model

[2Shir0]

   
Hello!

I'm quite new to 3d modelling, especially with texturing and shading.  I've downloaded the ACNH cat models, and upon exploring the texture files for Bob (The purple cat with the flower shirt), I found that there are many different layers for each texture. For example, every face texture has a universal roughness, metallic and occlusion maps, as well unique albedo, CRV, specular and normal maps. No issue though, after Following Fluffy McMalamute's excellent advice on this thread, I learnt how to apply all those textures on the same material. 


However  

After applying all the textures onto the materials, I found many of the materials don't blend with each other. To elaborate the model is split into 5 objects, the body ( which includes arms, legs, torso and back half of the head), the ears, the eyes (front upper quarter of head), the mouth  (front lower quarter of head) and the shirt. Because the head is split into 3 parts there are 3 different materials on the head. The Materials, whilst all aligned properly appear to be shaded differently and thus contrast each other. I've attached images below demonstrating what I've described. The underlined text labels what part of the head is what and I've pointed out where the contrast is. 
   
   
(Note, no contrast on ears as they share the same texture as the body)

I've also attached the shading setup below for reference. 
   
^Body Shading 
   
^Eye Shading
   
^Mouth Shading


Does anyone know how to mitigate this issue? any input is appreciated  
Also, Does anyone know what to do with the mTops_EdgCod.png texture? it's super not important but I have no idea how to use it! 


Thanks for any help I really appreciate it 
[size=1]same texture as the body)rs as they share the same texture as the body)[/size]

(Note, no contrast on ears as they share the same texture as the body)No                

(Note, no contrast on ears as they share the same texture as the body)