Sub model vs full model

Hi, 

I'm trying to use a submodel to get a deeper understanding of a complex part. I tried matching the reaction forces of the two models and there was a factor difference?  See below my approach used. I used 2D Shell models for the full model and 3D Tet mesh for the sub model. The flange face and SPC's are in the same location.

Is this approach correct?

What is the best way to verify the reaction forces are translated correctly?      

Sub model SPCM on flange face and pinned constraints at the hinges. 

Sub model load step - ULS case 3

Load step 3 from full model - ULS case 3