BB desperately needs to split them up for a task or something. Maybe even be really evil and hide one of them away for a while and pretend that "half" has been evicted.
We do not really know what these two men (they aren't boys as has been said) are really like as individuals. All we see is them jumping around like 9yr olds. I doubt as individuals they'd be doing much jumping and messing a around and then we might get a glimpse of their true personalities.
We know, from documentaries etc, that they don't always agree with each other.