Am I speaking into thin air?

When he comes out of the crate, he's very well-behaved. He likes to focus on tasks, which I happily give him. After about an hour he starts panting, not paying attention, nipping, harassing the other dog--that is what I consider misbehaving. I put him down and he goes to sleep pretty quickly.

I recently started putting him down right when he starts "misbehaving" and his "behaving" periods have lengthened. The entire day is more calm and he's better at interacting, staying with his tasks, and less frenzied than when I was having him sleep less.

The reason I made this post is because it seems like a bit much for him to be sleeping. I am wondering a) if too much sleep is possible for a BC and b) how other people have managed 5-month old BCs if they haven't been crating them. I would be shocked if people are leaving their puppies out in their house unsupervised for 5-6 hour stretches, or interacting with their BC puppies straight for 5-6 hour stretches every day.