Can you duplicate game & profile content onto a second xbox?

In most cases we are looking at Digital Games and which ever account is the primary an claimed most of the games should be considered Home account. Now if you have certain games perhaps your son has claimed and your account is the primary, you could set
each console at the others home console. So your home console would be the one your son uses and vice versa. Now when each is logged in, you have access to all of the games for your accounts, but you have access to all of the home console games. Just a thought
to think about, as a parent I claim all the games under just one account to make it easier. For game saves, most of that should be handled in the cloud and the use of an external HDD has helped out a lot with making a copy of the game/files from one an moving
to another and we had the ability to only move the games the child needed access to play as well by selecting the copy option to hard drive.

I think it would be easiest if your son loaded his profile on his new XBOX. So he would have his settings and his savegames. He normally downends the digital games that he also hears. You can declare its console as your home console, so it can play your
games again, which are also on your console.

It sounds like you need the recently added network transfer option, https://beta.support.xbox.com/help/hardware-network/console/enable-network-game-transfer-xbox-one.
This allows you to transfer your games and saves across your local network, at usually much faster speeds than re-downloading them again. Save game data is tied to your account, and will be retrieved when starting a game.

Your son could log in his account on the new console.

By doing it, the Xbox also asks if this should be the home console. If he set it up as his home console all digital purchases are available on that console for redownloading. Also if he already uses a external hdd you could just plug that in the new console.
In the storage settings he could transfer the data from that to the internal hdd. After that is done he could do the reverse thing with the external hdd on your console. This should be the faster way than redownloading all games which are on the internal hdd
on your console. also you could use the network game transfer aswell (https://beta.support.xbox.com/help/hardware-network/console/enable-network-game-transfer-xbox-one).

Please keep in mind, that the games should be purchased with the account from your son. If you made the purchase of the games with your account you need to set up the new console as your home console. In that case it will work through gameshare.

Hope that helps.

You cant

You MUST SIGN INTO the xbox account to download the content onto the pc

Then your brother must sign out and onto his own profile to play

A PROFILE can only be signed into one place at a time