Stoats and weasels are part of the Mustelidae family, as are otters/badgers/martens/polecats/minks & black footed ferrets and of course our domesticated ferrets, even mongoose and meercats are related. (other species may also be included!)
Point is, the dietary requirements of each species (although related) may be different. Many professionals agree that 'raw meat' diets for ferrets need supplementation. Considering the ferrets you have in your ownership now are 'domesticated' ferrets, in the sense that ferrets have been domesticated for around 2000 years now, they do not have a 'natu