Texture List and mismatched textures

So I am doing a 3d filter(the official plugin type would be a modeler).  I have been running into I setup a mesh with a some textures and some of the textures are mismatched.  Meaning region 1 gets the texture assigned to region 3, region 2 gets tht textures that is assigned to region 1, etc, etc.

So I have found a pattern to the weirdness, or so I think.

But here is the workflow of the 3d filter

- launch photoshop

- new document

- new layer from 3d filer or new 3d layer from preset(cone, sphere, etc) it does not matter

- run the 3d filter

- create mesh1 with texture named a.png

- create mesh2 with texture named b.png

- add a.png and b.png to texture list

Result is wrong: mesh1 has b.png and mesh2 has a.png, if I then take the existing scene that has the new meshes and then reapply the filter then the scene looks correct.

I then made of copy of a.png and named it c.png

Next workflow

- launch photoshop

- new document

- new layer from 3d filer or new 3d layer from preset(cone, sphere, etc) it does not matter

- run the 3d filter

- create mesh1 with texture named c.png

- create mesh2 with texture named b.png

- setup the texture list

- add b.png and c.png to texture list

Result is correct

So I went back to the first workflow but changed the last step

- launch photoshop

- new document

- new layer from 3d filer or new 3d layer from preset(cone, sphere, etc) it does not matter

- run the 3d filter

- create mesh1 with texture named a.png

- create mesh2 with texture named b.png

- setup the texture list

- reversed the order so that I added b.png and then a.png to texture list

Result is correct

So we have to sort the texture list in the magical order so that the right texture gets applied to the right material.  Can someone comment on what the magical order is?  The structures seem to imply material.map to textures would be resolved by name

I will look for a predictable way to order the texture list so that the right textures get applied to the right material maps, but perhaps others have had the same issues?