aww don't give up so soon! do you kennel them when you're at work? consider 2 kennels side by side each with their toys for when you are away. also to help them to play together put a tug of war toy between their kennels and they'll play together without being able to get at eachother. Now when you're around and can supervise the kennels come in handy when they get too rough.
Karly is the rowdy one in my bunch so when she won't stop torturing Nigel and I see he's had enough then it's "nap time" and off to their kennels they go.
Hope everything gets situated for the better.