I don't know what the procedures are at your airline KFTD, but at the airline I work for, when going for promotion to PU, we have to do a role play..the role play being a conflict between 2 crew members. This should be something that should be "taught" to all PU I think.
As someone else has said, I prefer to keep what happens on the aircraft, on the aircraft and not bring it to the office. If you happen to fly with these people again, my advice would be to take them to one side and just ask them what the problem is. Or ask them if things are ok...what you don't want is an atmosphere between crew members as this spread through the whole crew like wild fire!
You say they're new. I can understand how this may be a reason as well. I have flown with new crew before and it's seemed that they have found it hard to get used to the way things are done between crew members.
The role of a PU sometimes does take up a lot of time and effort and the help of crew members is always appreciated. To ask someone to do a gash I feel is not a problem in the slightest. One of the aims in a flight is to get the job done and the help of other crew members is always going to be something PU's need.
I hope this does sort itself out for you. If things persist then you need to take a FIRM step with them. Assessments, offloading (if needed).
Good luck! Let us know how it goes!