"Borderlines also do these behaviors but Narcissistic and Borderline PD's go together very well and often people are NPD/BPD combos. " quote RedEagle

Yes, I can see this happening because of how someone with BPD is already conditioned to be treated the way individuals with NPD treat others as that is what they grew up with, it is "their" normal. I am understanding you to mean this as people with NPD and BPD become couples that become parents and end up bringing up children that themselves become challenged as well, which probably just repeats the dysfunctional cycle to take place. Oh how sad that is to think about.