How safe is my pug with Jack Russells

Question
My best friend has two female Jack Russells. She got them together as litter mates and they're about 6 months old.  I have a young pug.  I took thim to visit when he was about 13 weeks old and the JRT's were quite aggressive. One in particular (the dominant one) really turned on him and I was very alarmed. My friend kept them at bay and kept saying that they were really quite sweet but I noticed that they constantly fight with each other! I have not been round again for over a month but this is becoming difficult as I don't want to 'offend'. However, I've read about JRT's agression and am afraid they could do severe damage to my poor pug. I think my friend has a problem with them, but I doubt she'd admit it.  What do you think I should do?
Many thanks.

Answer
Hi Julia,
 I missed that these were bitches.  Oh Geeez.  I have had my worst fights with bitches.  My males may have a small altercation about twice a year that is usually caused by a peice of food on the floor.  I can call them off in an instant.  I never leave them alone when I am not here.

 Jacks are very cute and TV's Frazier, Moose has made this breed very desirable.  Unfortunately not very many people know that this was a rescue dog.  He has his own issues that are not shown on TV.  He has many, many ,many HOURS of training by a professional dog trainer who can spend 24-7 with him. Which I doubt this lady has that much time or energy to spend with these dogs.

 I don't hold a breeder very high if they sell littermates to one person.  I will never do it.  If you need any back up have her write me and I will ask her questions that she will most likely answer yes.

Good luck,
Tammy