2x7 year old spaniel Xs (sisters) I new Jack Russell X puppy 6 weeks

Question
I have two Springer X Field spaniels, they are sisters, both have been spayed. Friend brought me a Jack Russell X puppy aged 6 weeks. My girls won't go near him, seem terrified of him. I am paying more attention to my 2 girls than the puppy, have got my daughters to do more with the puppy, since I am 'pack leader'. Three dogs, I know, now class as a pack, so I have to be careful this puppy doesn't encourage fights. Have the puppy in a cage, his place of security, and peace for my dogs. They won't even go near the cage, they smell the air from some distance. It's been three days now and they haven't made any move towards the puppy. My girls sleep outside, although having to keep puppy inside until they accept him.
Is this normal? Is there anything I can do to help them accept him? Have tried rubbing the puppy over with a towel that I've used on the older dogs, trying to transfer some of their scent onto him. Have heard that rubbing him with mint leaves might help, then put the smell of mint onto my dogs noses (heard this about a horse and foal). What do you think?

Answer
Many dogs once they are past about 3 years old want nothing to do with puppies and their sharp little teeth and biting games.  I can see the fear too if an older dog has not had regular contact with puppies.  They will see him as an unwelcome intruder.  Be very careful not to leave him alone with them.  

We have just imposed the fourth new puppy on our 13 old Lab Aster since she came to live us 3 years ago.  She wants nothing to do with them or other puppies that come to visit.  Your girls may eventually tolerate him, but I wouldn't expect them to ever play much with him.  Allow them to give him warning snaps and barks.  Discourage him from insisting they play with him.  i don't think there is that much else you can do.  We introduced 2 of the puppies to Aster at her old home where she stayed while we went to pickup the puppy.  The neutral ground didn't help, although she may still see it as her home too.