Yes it has to do with managing skin
You want multiple skin used in your map right?
Like you've said
Ogre
Ogre lord
Ogre zombie
Ogre crusher (only example)
Then, open up the magos model editor, search for the model you wanted, open it, open the texture window ( window -> texture manager), then import your desired skin to the model, open up the material manager (window -> material manager), then search the default ogre skin, and change them all to the imported ones, and don't forget to change the portrait as well