I think the first concern is... is your 6m/o male fixed...
I had a couple dogs growing up who refused to sleep in seperate kennels, we let them share a space. Mind you they were brothers from the same litter and were only in kennels at night... but they loved napping together in them. Mind you this crate was big enough for a great dane and my li'l boys were 15lbs each.
Each dog had a very strong bond to a family member. One was very bonded to me, the other was very bonded to my mom&sister. I think it depends on the dogs... I would for now seperate them and make sure you are building your own bond with each dog until they are older
