Hi Scott!
Without more information I can’t tell you exactly why this has happened to your model. It’s usually the result of some sort of point order mismatch, or possibly a UV issue if your model has UVs applied. I would have to know more about your process to guess where this might have gone wrong.
However, in terms of general Transpose Master usage, the tool works best on a mesh with multiple levels of subdivision and a lower poly base level. This should be true for all of the visible subtools you are including in your t-pose mesh.
The idea is that the high detail subtools are merged together into a new combined subtool at the lowest level of subdivision, which is going to be much easier to pose and correct surface distortion on. That merged tool is then posed or deformed as desired, and the changes are transferred back to the high detail versions of all the individual subtools in the original tool.
If your tool was not in this form–for instance a high poly mesh at a single level of subdivision–you will want to convert it for best results in this process. You can ZRemesh your mesh, or a duplicate of it, into a newer lower poly version, subdivide it sufficiently to hold the incoming detail, and project the detail from the original mesh onto it. Make sure you do the same for all visible subtools going into the Tpose mesh.