They all actually take on the same humanoid form and they all meet masked (the masks could give away which is which, but isn't necessary) and different ones lead for different tasks. That way the "villain" can appear to be in multiple places at the same and if one of them is ever killed, the "villain" appears to still be alive and well. After a period of time a new shapeshifter is recruited (through intermediaries) so the organization never really knows which one they're talking to/about/taking orders from.