Whats the difference between a russian dwarf hamster and a fancy dwarf hamster?

i have to russian dwarfs livin together in a 5 story cage. my bro has a fancy dwarf livin in a 1 story cage. im wonderin what the difference is between them because people keep tellin me they are the same as campells dwarf and the winter white. i just want to know if this is true. if its not can i keep them all together when im cleanin my many pets cages?? it takes me about 20 minutes to clean my gecko,hamster,my bros hamter, hermit ,and birds cage. is this alright??