I know it sounds bad but i had the same problems putting two one year old hobs together that had never been kept with other ferrets before, they wanted to rip chunks out of each other, i tried leaving them to sort it out and it didnt, so i decided to put them together in the cage and wait just outside it, as soon as they both started id hit them and throw them back in, they started again so again i hit them and threw them back in, then after probabaly 5 times as soon as they started and saw my hand going to the cage latch they would both run to the nest box shitting themselves, only had to do